Rocket Fuel Inactive 10-K28 Feb 142013 FY Annual reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
Document and Entity Information (USD $)	Dec. 31, 2013	Feb. 20, 2014
Document and Entity Information	'	'
Entity Registrant Name	'Rocket Fuel Inc.	'
Entity Central Index Key	'0001477200	'
Document Type	'10-K	'
Document Period End Date	31-Dec-13	'
Amendment Flag	'false	'
Current Fiscal Year End Date	'--12-31	'
Entity Well-known Seasoned Issuer	'No	'
Entity Voluntary Filers	'No	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Non-accelerated Filer	'
Entity Public Float	$314,708,833	'
Entity Common Stock, Shares Outstanding	'	35,054,189
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'FY	'

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Current Assets:	'	'
Cash and cash equivalents	$113,873	$14,896
Accounts receivable, net	90,502	47,333
Deferred tax assets	207	334
Prepaid expenses	2,164	962
Other current assets	3,962	253
Total current assets	210,708	63,778
Property, equipment and software, net	25,794	10,939
Other assets	1,006	472
Total assets	237,508	75,189
Current Liabilities:	'	'
Accounts payable	39,910	17,482
Accrued and other current liabilities	21,584	6,186
Deferred revenue	918	187
Current portion of capital leases	203	'
Current portion of debt	7,243	1,988
Total current liabilities	69,858	25,843
Long-term debt-Less current portion	19,568	4,978
Capital leases-Less current portion	412	'
Deferred rent-Less current portion	3,909	430
Deferred tax liabilities	207	334
Convertible preferred stock warrant liability	'	2,741
Other liabilities	387	'
Total liabilities	94,341	34,326
Commitments and contingencies (Note 12)	'	'
Stockholders' Equity	'	'
Common stock, $0.001 par value- 1,000,000,000 and 35,850,100 authorized as of December 31, 2013 and 2012, respectively; 32,825,992 and 8,680,041 issued and outstanding as of December 31, 2013, and 2012, respectively	33	8
Additional paid-in capital	187,624	3,865
Accumulated other comprehensive loss	-15	-84
Accumulated deficit	-44,475	-23,543
Total stockholders' equity	143,167	40,863
Total liabilities and stockholders' equity	237,508	75,189
Series A	'	'
Stockholders' Equity	'	'
Convertible preferred stock	'	9,788
Series B	'	'
Stockholders' Equity	'	'
Convertible preferred stock	'	9,935
Series C	'	'
Stockholders' Equity	'	'
Convertible preferred stock	'	6,501
Series C-1	'	'
Stockholders' Equity	'	'
Convertible preferred stock	'	$34,393

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized	1,000,000,000	35,850,100
Common stock, shares issued	32,825,992	8,680,041
Common stock, shares outstanding	32,825,992	8,680,041
Series A	'	'
Convertible preferred stock, par value (in dollars per share)	$0.00	$0.00
Convertible preferred stock, shares authorized	'	10,884,902
Convertible preferred stock, shares issued	'	10,618,372
Convertible preferred stock, shares outstanding	'	10,618,372
Series B	'	'
Convertible preferred stock, par value (in dollars per share)	$0.00	$0.00
Convertible preferred stock, shares authorized	'	4,811,855
Convertible preferred stock, shares issued	'	4,811,855
Convertible preferred stock, shares outstanding	'	4,811,855
Series C	'	'
Convertible preferred stock, par value (in dollars per share)	$0.00	$0.00
Convertible preferred stock, shares authorized	'	1,116,030
Convertible preferred stock, shares issued	'	1,116,030
Convertible preferred stock, shares outstanding	'	1,116,030
Series C-1	'	'
Convertible preferred stock, par value (in dollars per share)	$0.00	$0.00
Convertible preferred stock, shares authorized	'	2,975,228
Convertible preferred stock, shares issued	'	2,932,675
Convertible preferred stock, shares outstanding	'	2,932,675

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
CONSOLIDATED STATEMENTS OF OPERATIONS	'	'	'
Revenue	$240,605	$106,589	$44,652
Cost of revenue	125,520	60,011	27,300
Gross profit	115,085	46,578	17,352
Operating expenses:	'	'	'
Research and development	17,714	4,876	1,545
Sales and marketing	83,345	41,069	17,256
General and administrative	28,708	8,403	2,336
Total operating expenses	129,767	54,348	21,137
Loss from operations	-14,682	-7,770	-3,785
Other expense, net:	'	'	'
Interest expense	-917	-316	-250
Other income (expense)-net	-308	135	33
Change in fair value of convertible preferred stock warrant liability	-4,740	-2,308	-295
Other expense, net	-5,965	-2,489	-512
Loss before income taxes	-20,647	-10,259	-4,297
Provision for income taxes	-285	-84	-28
Net loss	($20,932)	($10,343)	($4,325)
Basic and diluted net loss per share attributable to common stockholders (in dollars per share)	($1.38)	($1.29)	($0.57)
Basic and diluted weighted-average shares used to compute net loss per share attributable to common stockholders (in shares)	15,177	8,024	7,600

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS	'		'		'
Net loss	($20,932)		($10,343)		($4,325)
Other comprehensive loss:	'		'		'
Foreign currency translation adjustments	69	[1]	-77	[1]	-6	[1]
Comprehensive loss	($20,863)		($10,420)		($4,331)

[1]	Reclassifications out of Other comprehensive loss into Net loss were not significant.

CONSOLIDATED_STATEMENTS_OF_STO

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $)	Total		Series C	Series C-1	Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
In Thousands, except Share data, unless otherwise specified	Total		Series C	Series C-1	Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance at Dec. 31, 2010	$10,982		'	'	$19,723	$7	$128	($1)	($8,875)
Balance (in shares) at Dec. 31, 2010	'		'	'	15,430,227	7,525,852	'	'	'
Increase (Decrease) in Stockholders' Equity	'		'	'	'	'	'	'	'
Issuance of stock, net of issuance costs	6,501		6,501	'	'	'	'	'	'
Issuance of stock, net of issuance costs (in shares)	'		1,116,030	'	'	'	'	'	'
Issuance of common stock upon exercises of employee stock options, net of repurchases	72		'	'	'	'	72	'	'
Issuance of common stock upon exercises of employee stock options, net of repurchases (in shares)	'		'	'	'	333,104	'	'	'
Issuance of restricted common stock	54		'	'	'	'	54	'	'
Issuance of restricted common stock (in shares)	'		'	'	'	68,815	'	'	'
Stock-based compensation	110		'	'	'	'	110	'	'
Foreign currency translation adjustment	-6	[1]	'	'	'	'	'	-6	'
Net loss	-4,325		'	'	'	'	'	'	-4,325
Balance at Dec. 31, 2011	13,388		'	'	26,224	7	364	-7	-13,200
Balance (in shares) at Dec. 31, 2011	'		'	'	16,546,257	7,927,771	'	'	'
Increase (Decrease) in Stockholders' Equity	'		'	'	'	'	'	'	'
Issuance of stock, net of issuance costs	34,393		'	34,393	'	'	'	'	'
Issuance of stock, net of issuance costs (in shares)	'		'	2,932,675	'	'	'	'	'
Issuance of common stock upon exercises of employee stock options, net of repurchases	181		'	'	'	1	180	'	'
Issuance of common stock upon exercises of employee stock options, net of repurchases (in shares)	'		'	'	'	738,699	'	'	'
Issuance of restricted common stock	33		'	'	'	'	33	'	'
Issuance of restricted common stock (in shares)	'		'	'	'	13,571	'	'	'
Stock-based compensation	3,288		'	'	'	'	3,288	'	'
Foreign currency translation adjustment	-77	[1]	'	'	'	'	'	-77	'
Net loss	-10,343		'	'	'	'	'	'	-10,343
Balance at Dec. 31, 2012	40,863		'	'	60,617	8	3,865	-84	-23,543
Balance (in shares) at Dec. 31, 2012	'		'	'	19,478,932	8,680,041	'	'	'
Increase (Decrease) in Stockholders' Equity	'		'	'	'	'	'	'	'
Issuance of stock, net of issuance costs	103,307		'	'	'	4	103,303	'	'
Issuance of stock, net of issuance costs (in shares)	'		'	'	'	4,000,000	'	'	'
Issuance of common stock upon exercises of employee stock options, net of repurchases	637		'	'	'	1	636	'	'
Issuance of common stock upon exercises of employee stock options, net of repurchases (in shares)	'		'	'	'	400,489	'	'	'
Conversion of convertible preferred stock to common stock	'		'	'	-60,617	19	60,598	'	'
Conversion of convertible preferred stock to common stock (in shares)	'		'	'	-19,478,932	19,478,932	'	'	'
Conversion of convertible preferred stock warrants to common stock	7,580		'	'	'	1	7,579	'	'
Conversion of convertible preferred stock warrants to common stock (in shares)	'		'	'	'	266,530	'	'	'
Stock-based compensation	11,643		'	'	'	'	11,643	'	'
Foreign currency translation adjustment	69	[1]	'	'	'	'	'	69	'
Net loss	-20,932		'	'	'	'	'	'	-20,932
Balance at Dec. 31, 2013	$143,167		'	'	'	$33	$187,624	($15)	($44,475)
Balance (in shares) at Dec. 31, 2013	'		'	'	'	32,825,992	'	'	'

[1]	Reclassifications out of Other comprehensive loss into Net loss were not significant.

CONSOLIDATED_STATEMENTS_OF_STO1

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2012
	Series C	Series C-1
Issuance of stock, price per share (in dollars per share)	$5.87	$11.76
Issuance of stock, issuance costs	$49	$107

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
OPERATING ACTIVITIES:	'	'	'
Net loss	($20,932)	($10,343)	($4,325)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'	'
Depreciation and amortization	7,854	3,600	1,922
Provision for doubtful accounts	569	285	203
Stock-based compensation	10,921	3,288	110
Issuance of restricted stock	'	33	54
Amortization of debt discount	7	8	13
Loss on disposal of leases, property, equipment and software	441	63	'
Change in fair value of preferred stock warrant liability	4,740	2,308	295
Changes in operating assets and liabilities:	'	'	'
Accounts receivable	-43,803	-31,129	-10,005
Prepaid expenses	-1,195	-624	-136
Other current assets	-3,571	-127	-17
Other assets	-416	-389	37
Accounts payable	21,009	9,612	3,580
Accrued and other liabilities	14,317	4,066	1,065
Deferred rent	3,189	359	81
Deferred revenue	732	187	-8
Net cash used in operating activities	-6,138	-18,803	-7,131
INVESTING ACTIVITIES:	'	'	'
Purchases of property, equipment and software	-14,294	-4,089	-1,964
Capitalized internal use software development costs	-5,592	-4,674	-2,629
Net cash used in investing activities	-19,886	-8,763	-4,593
FINANCING ACTIVITIES:	'	'	'
Proceeds from the issuance of common stock in initial public offering, net of underwriting discounts and commission	107,880	'	'
Issuance costs related to initial public offering	-4,268	'	'
Proceeds from the issuance of convertible preferred stock	'	34,500	6,550
Proceeds from the exercise of common stock warrants	97	'	'
Issuance costs related to convertible preferred stock	'	-107	-49
Proceeds from exercise of vested common stock options	243	54	28
Proceeds from early exercise of unvested common stock options	1,070	460	124
Repurchases of common stock options early exercised	-10	-2	-1
Borrowings from line of credit or revolving credit facility, net of debt issuance costs	16,893	4,000	2,000
Repayment of line of credit or revolving credit facility	-11,853	-6,000	'
Proceeds from issuance of long-term debt, net of debt issuance costs	29,911	5,000	'
Repayment of long-term debt	-15,114	-421	-370
Net cash provided by financing activities	124,849	37,484	8,282
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	152	-93	-10
CHANGE IN CASH AND CASH EQUIVALENTS	98,977	9,825	-3,452
CASH AND CASH EQUIVALENTS-Beginning of period	14,896	5,071	8,523
CASH AND CASH EQUIVALENTS-End of period	113,873	14,896	5,071
SUPPLEMENTAL DISCLOSURES OF OTHER CASH FLOW INFORMATION:	'	'	'
Cash paid for income taxes	492	'	'
Cash paid for interest	835	286	202
SUPPLEMENTAL DISCLOSURES OF NONCASH INVESTING AND FINANCING ACTIVITIES:	'	'	'
Purchases of property and equipment recorded in accounts payable and accruals	2,349	882	55
Deferred offering costs recorded in accrued liabilities	413	15	'
Property, plant and equipment under capital lease obligations	615	'	'
Vesting of early exercised options	416	125	10
Stock-based compensation capitalized in internally developed software costs	722	'	'
Conversion of convertible preferred stock to common stock	60,617	'	'
Conversion of preferred stock warrants to common stock	$7,481	'	'

NATURE_OF_BUSINESS_AND_SUMMARY

NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2013
NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	'
NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	'

	NOTE 1. NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

	Rocket Fuel Inc. (the "Company") was incorporated as a Delaware corporation on March 25, 2008. The Company is a provider of an artificial-intelligence digital advertising solution. The Company is headquartered in Redwood City, California, and has offices in seven cities in the United States. The Company established a wholly-owned subsidiary in the United Kingdom, with an office in the Netherlands, in 2011 and wholly-owned subsidiaries in Germany and Canada in 2013.

	In September 2013, the Company completed the initial public offering of its common stock (the "IPO") whereby 4,000,000 shares of common stock were sold by the Company and 600,000 shares of common stock were sold by selling stockholders. The public offering price of the shares sold in the offering was $29.00 per share. The Company did not receive any proceeds from the sale of shares by the selling stockholders. The total gross proceeds from the offering to the Company were $116.0 million. After deducting underwriters' discounts and commissions and offering expenses, the aggregate net proceeds received by the Company totaled approximately $103.3 million.

	Basis of Presentation—The accompanying consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business.

	Principles of Consolidation—The consolidated financial statements include the Company and its wholly-owned subsidiary, Rocket Fuel, Ltd., an England and Wales corporation, which is engaged in marketing and selling advertising campaigns. All intercompany transactions and balances have been eliminated in consolidation.

	Use of Estimates—The preparation of consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.

	Certain Significant Risks and Uncertainties—The Company is subject to those risks common in technology-driven markets, including, but not limited to, competitive forces, dependence on key personnel, customer demand for its solution, management of growth, the successful protection of its proprietary technologies, compliance with government regulations, and the possibility of not being able to obtain additional financing when needed.

	Foreign Currency Translation—The Company's foreign subsidiary records its assets, liabilities and results of operations in its local currency, which is their functional currency. The Company translates its subsidiary consolidated financial statements into U.S. dollars each reporting period for purposes of consolidation.

	Assets and liabilities of the Company's foreign subsidiary are translated at the period-end currency exchange rates, certain equity accounts are translated at historical exchange rates while revenue, expenses, gains and losses are translated at the average currency exchange rates in effect for the period. The effects of these translation adjustments are reported in a separate component of stockholders' equity titled accumulated other comprehensive loss.

	Fair Value of Financial Instruments—The Company's financial instruments consist principally of cash equivalents, accounts receivable, accounts payable, accrued liabilities, capital lease, term debt and line of credit. The fair value of the Company's cash equivalents is determined based on quoted prices in active markets for identical assets for its money market funds. The recorded values of the Company's accounts receivable, accounts payable and accrued liabilities approximate their current fair values due to the relatively short-term nature of these accounts. The Company believes that the fair value of the capital lease, term debt and line of credit approximates its recorded amount at December 31, 2013 as the interest rate on the capital lease, term debt and line of credit is variable and is based on market interest rates after consideration of default and credit risk.

	Cash and Cash Equivalents—Cash consists of cash maintained in checking and savings accounts. All highly liquid investments purchased with an original maturity date of 90 days or less at the date of purchase are considered to be cash equivalents. Cash equivalents consist of money market funds.

	Concentration of Credit Risk—Financial instruments, which potentially subject the Company to significant concentrations of credit risk, consist primarily of cash and accounts receivable. A significant portion of the Company's cash is held at one major financial institution, which management assesses to be of high credit quality. The Company has not experienced any losses in such accounts.

	The Company mitigates its credit risk with respect to accounts receivable by performing credit evaluations and monitoring its customers' accounts receivable balances. As of December 31, 2013, no single customer accounted for more than 10% of accounts receivable. As of December 31, 2012, one customer accounted for more than 10% of accounts receivable.

	During the years ended December 31, 2013, 2012 and 2011, no single customer represented more than 10% of revenue.

	Provision for Doubtful Accounts—The Company records a provision for doubtful accounts based on historical experience and a detailed assessment of the collectability of its accounts receivable. In estimating the allowance for doubtful accounts, management considers, among other factors, the aging of the accounts receivable, historical write-offs and the credit-worthiness of each customer. If circumstances change, such as higher-than-expected defaults or an unexpected material adverse change in a major customer's ability to meet its financial obligations, the Company's estimate of the recoverability of the amounts due could be reduced by a material amount.

	The following table presents the changes in the allowance for doubtful accounts (in thousands):


		Year Ended December 31,
		2013		2012			2011
	Allowance for doubtful accounts:
	Balance, beginning of period	$	468	$	203		$	—
	Add: bad debt expense		569		285			203
	Less: write-offs, net of recoveries		20		(20	)		—


	Balance, end of period	$	1,057	$	468		$	203





	Property and Equipment—Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization is computed using the straight-line method over the estimated useful lives of the related assets. Maintenance and repairs are charged to expense as incurred, and improvements and betterments are capitalized. When assets are retired or otherwise disposed of, the cost and accumulated depreciation or amortization, as applicable, are removed from the balance sheet and any resulting gain or loss is reflected in operations in the period realized.

	Construction in progress primarily includes costs related to the leasehold improvements associated with our new corporate headquarters in Redwood City, California and the recently leased New York, New York sales office. Construction in progress also includes network equipment infrastructure to support our data centers around the world. Interest capitalized during the periods presented was not material.

	Leasehold improvements are amortized on a straight-line basis over the term of the lease, or the useful life of the assets, whichever is shorter. Depreciation and amortization periods for the Company's property and equipment are as follows:


	Asset Classification	Estimated Useful Life
	Computer hardware and purchased software	2 - 3 years
	Capitalized internal-use software costs	2 - 3 years
	Office equipment, furniture and fixtures	5 years

	Internal-Use Software Development Costs—The Company incurs costs to develop software for internal use. The Company expenses all costs that relate to the planning and post implementation phases of development as research and development expense. The Company capitalizes costs when preliminary efforts are successfully completed, management has authorized and committed project funding, and it is probable that the project will be completed and will be used as intended. Costs incurred for enhancements that are expected to result in additional material functionality are capitalized. The Company capitalized $6.3 million, $4.7 million and $2.6 million in internal-use software costs during the years ended December 31, 2013, 2012 and 2011, respectively, which are included in property, equipment and software—net on the consolidated balance sheets.

	Amortization commences when the website or software for internal use is ready for its intended use and the amortization period is the estimated useful life of the related asset, which is generally three years. Amortization expense totaled $3.4 million, $2.3 million and $1.5 million for the years ended December 31, 2013, 2012 and 2011, respectively.

Impairment of Long-lived Assets—The Company periodically reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset is impaired or the estimated useful lives are no longer appropriate. If indicators of impairment exist and the undiscounted projected cash flows associated with such assets are less than the carrying amount of the asset, an impairment loss is recorded to write the assets down to their estimated fair values. Fair value is estimated based on discounted future cash flows. No impairment charges were recorded during the years ended December 31, 2013, 2012 and 2011.

Revenue Recognition—The company generates revenue by delivering digital advertisements to Internet users through various channels, including display, mobile, social and video.

The Company recognizes revenue when all four of the following criteria are met:



•
Persuasive evidence of an arrangement exists

•
Delivery has occurred or a service has been provided

•
Customer fees are fixed or determinable

•
Collection is reasonably assured

Revenue arrangements are evidenced by a fully executed insertion order ("IO"). Generally, IOs state the number and type of advertising impressions (cost-per-thousand) to be delivered, the agreed upon rate for each delivered impression, and a fixed period of time for delivery.

The Company determines collectability by performing ongoing credit evaluations and monitoring its customers' accounts receivable balances. For new customers and their agents, which may be advertising agencies or other third parties, the Company performs a credit check with an independent credit agency and may check credit references to determine creditworthiness. The Company only recognizes revenue when collection is reasonably assured.

In the normal course of business, the Company frequently contracts with advertising agencies on behalf of their advertiser clients. The determination of whether revenue should be reported on a gross or net basis is based on an assessment of whether the Company is acting as the principal or an agent in the transaction. In determining whether the Company acts as the principal or an agent, the Company follows the accounting guidance for principal-agent considerations. While none of the factors identified in this guidance is individually considered presumptive or determinative, because the Company is the primary obligor and is responsible for (i) fulfilling the advertisement delivery, (ii) establishing the selling prices for delivery of the advertisements, and (iii) performing all billing and collection activities including retaining credit risk, the Company has concluded that it acts as the principal in the majority of these arrangements and therefore reports revenue earned and costs incurred on a gross basis.

On occasion, the Company has offered customer incentive programs which provide rebates after achieving a specified level of advertising spending. The Company records reductions to revenue for estimated commitments related to these customer incentive programs. For transactions involving incentives, the Company recognizes revenue net of the estimated amount to be paid by rebate, provided that the rebate amount can be reasonably and reliably estimated and the other conditions for revenue recognition have been met. The Company's policy requires that, if rebates cannot be reliably estimated, revenue is not recognized until reliable estimates can be made or the rebate program lapses.

Multiple-Element Arrangements—The Company enters into arrangements to sell advertising that includes different media placements or ad services that are delivered at the same time, or within close proximity of one another. Beginning on January 1, 2011, the Company adopted new authoritative guidance on multiple element arrangements, using the prospective method for all arrangements entered into or materially modified from the date of adoption. Under this new guidance, the Company allocates arrangement consideration in multiple-deliverable revenue arrangements at the inception of an arrangement to all deliverables or those packages in which all components of the package are delivered at the same time, based on the relative selling price method in accordance with the selling price hierarchy, which includes: (1) vendor-specific objective evidence ("VSOE"), if available; (2) third-party evidence ("TPE"), if VSOE is not available; and (3) best estimate of selling price ("BESP"), if neither VSOE nor TPE is available.

VSOE—The Company determines VSOE based on its historical pricing and discounting practices for the specific product or service when sold separately. In determining VSOE, the Company requires that a substantial majority of the stand-alone selling prices for these services fall within a reasonably narrow pricing range. The Company has not been able to establish VSOE for any of its advertising offerings.

TPE—When VSOE cannot be established for deliverables in multiple element arrangements, the Company applies judgment with respect to whether it can establish a selling price based on TPE. TPE is determined based on competitor prices for similar deliverables when sold separately. Generally, the Company's go-to-market strategy differs from that of its peers and its offerings contain a significant level of differentiation such that the comparable pricing of services cannot be obtained. Furthermore, the Company is unable to reliably determine the selling prices of similar competitor services on a stand-alone basis. As a result, the Company has not been able to establish selling price based on TPE.

BESP—When it is unable to establish selling price using VSOE or TPE, the Company uses BESP in its allocation of arrangement consideration. The objective of BESP is to determine the price at which the Company would transact a sale if the service were sold on a stand-alone basis. BESP is generally used to allocate the selling price to deliverables in the Company's multiple element arrangements. The Company determines BESP for deliverables by considering multiple factors, including, but not limited to, prices it charges for similar offerings, market conditions, competitive landscape and pricing practices. In particular, the Company reviews multiple data points to determine BESP, including price lists used by the Company's sales team in pricing negotiations, historical average and median pricing achieved in prior contractual customer arrangements and input from the Company's sales operation department regarding what it believes the deliverables could be sold for on a stand-alone basis. BESP is determined at an advertising unit level that is consistent with the Company's underlying market strategy and stratified based on specific consideration of channel, geography, industry and size, as deemed necessary.

The Company limits the amount of allocable arrangement consideration to amounts that are fixed or determinable and that are not contingent on future performance or future deliverables. The Company will regularly review BESP. Changes in assumptions or judgments or changes to the elements in the arrangement could cause a material increase or decrease in the amount of revenue that the Company reports in a particular period.

The Company recognizes the relative fair value of advertising services as they are delivered, assuming all other revenue recognition criteria are met. Deferred revenue is comprised of contractual billings in excess of recognized revenue and payments received in advance of revenue recognition.

Cost of Revenue—Cost of revenue consists primarily of media cost for advertising impressions purchased from real-time advertising exchanges and other third parties. Cost of revenue also includes third-party data center costs and the salaries and related costs of the Company's operations group. This group sets up, initiates and monitors the Company's advertising campaigns. In addition, depreciation of the data center equipment, rental payments to third-party vendors for data centers and amortization of capitalized internal-use software are included in cost of revenue.

Research and Development—Research and development expenses include costs associated with the maintenance and ongoing development of the Company's technology, including compensation and employee benefits and allocated costs associated with the Company's engineering and research and development departments, as well as costs for contracted services and supplies. Allocated costs include charges for facilities, office expenses, telephones, and other miscellaneous expenses. The Company reviews costs incurred in the application development stage and assesses such costs for potential capitalization.

Sales and Marketing—Sales and marketing expenses consist primarily of compensation (including commissions) and employee benefits of sales and marketing personnel and related support teams, allocated costs, certain advertising costs, travel, trade shows and marketing materials. Allocated costs include charges for facilities, office expenses, telephones, and other miscellaneous expenses. The Company incurred advertising costs of $3.6 million, $0.1 million and $0.1 million for the years ended December 31, 2013, 2012 and 2011, respectively.

General and Administrative—General and administrative expenses include facilities costs, executive and administrative compensation and employee benefits, depreciation, professional services fees, insurance costs, bad debt and other allocated costs, such as facility-related expenses, supplies and other fixed costs. Allocated costs include charges for facilities, office expenses, telephones, and other miscellaneous expenses.

Stock-based Compensation—The Company measures compensation expense for all stock-based payment awards, including stock options granted to employees, based on the estimated fair values on the date of the grant. The fair value of each stock option granted is estimated using the Black-Scholes option pricing model. Stock-based compensation is recognized on a straight-line basis over the requisite vesting period, net of estimated forfeitures. The forfeiture rate is based on an analysis of the Company's actual historical forfeitures.

The Company accounts for stock options issued to non-employees based on the fair value of the awards determined using the Black-Scholes option pricing model. The fair value of stock options granted to non-employees is re-measured as the stock options vest, and the resulting change in fair value, if any, is recognized in the Company's consolidated statement of operations during the period the related services are rendered, generally between one and four years.

Preferred Stock Warrant Liability—Freestanding warrants related to shares that are redeemable or contingently redeemable are classified as a liability on the Company's consolidated balance sheets. The fully vested convertible preferred stock warrants were subject to re-measurement at each balance sheet date, and any change in fair value is recognized as a component of other expense, net. As completion of the Company's initial public offering constituted a liquidation event, the convertible preferred stock warrants were converted into common stock or warrants to purchase common stock, and the liability was reclassified to additional paid-in capital as of December 31, 2013.

Income Taxes—The Company accounts for income taxes using an asset and liability approach. Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Operating loss and tax credit carry-forwards are measured by applying currently enacted tax laws. Valuation allowances are provided when necessary to reduce net deferred tax assets to an amount that is more likely than not to be realized. Due to uncertainty as to the realization of benefits from deferred tax assets, including net operating loss carry-forwards, research and development and other tax credits, the Company has provided a full valuation allowance reserved against such assets as of December 31, 2013, 2012 and 2011.

The Company recognizes the tax effects of an uncertain tax position only if it is more likely than not to be sustained based solely on its technical merits as of the reporting date, and then, only in an amount more likely than not to be sustained upon review by the tax authorities. The Company considers many factors when evaluating and estimating its tax positions and tax benefits, which may require periodic adjustments and which may not accurately anticipate actual outcomes.

Comprehensive Income (Loss)—In June 2011, the Financial Accounting Standards Board ("FASB") issued an accounting standards update that requires an entity to present the total of comprehensive income, the components of net income and the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements. This guidance eliminates the option to present the components of other comprehensive income as part of the statement of equity. The Company retrospectively adopted these new standards in the first quarter of 2012 and has presented a separate consolidated statement of comprehensive loss for the years ended December 31, 2013, 2012 and 2011.

Deferred Offering Costs—Deferred offering costs consisted primarily of direct incremental costs related to the Company's initial public offering of its common stock. Approximately $0.1 million of deferred offering costs are included in other assets on the Company's consolidated balance sheets as of December 31, 2013 and 2012, respectively. Upon completion of the initial public offering, these amounts were offset against the proceeds of the offering.

Recently Issued and Adopted Accounting Pronouncements—Under the Jumpstart Our Business Startups Act, or JOBS Act, we qualify as an "emerging growth company." We have irrevocably elected to opt out of the extended transition period for complying with new or revised accounting standards pursuant to Section 107(b) of the JOBS Act, and, therefore, we will be subject to the same new or revised accounting standards as other public companies that are not "emerging growth companies."

In February 2013, the FASB issued guidance that addresses the presentation of amounts reclassified from accumulated other comprehensive income. This guidance does not change current financial reporting requirements. Instead, an entity is required to cross-reference to other required disclosures that provide additional detail about amounts reclassified out of accumulated other comprehensive income. In addition, the guidance requires an entity to present significant amounts reclassified out of accumulated other comprehensive income by line item of net income if the amount reclassified is required to be reclassified to net income in its entirety in the same reporting period. Adoption of this standard is required for periods beginning after December 15, 2012 for public companies. The adoption of this accounting standard did not have an impact on our consolidated financial position, results of operations and cash flows.

In July 2013, the Financial Accounting Standards Board issued Accounting Standards Update (ASU) No. 2013-11, Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (ASU 2013-11). The guidance requires an entity to present its unrecognized tax benefits net of its deferred tax assets when settlement in this manner is available under the tax law, which would be based on facts and circumstances as of the balance sheet reporting date and would not consider future events. Gross presentation of unrecognized tax benefit will still be required in the notes to the financial statements. ASU 2013-11 will apply on a prospective basis to all unrecognized tax benefits that exist at the effective date. This ASU is effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. The adoption of ASU 2013-11 is not expected to have a material impact on our consolidated financial statements.

FAIR_VALUE_MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
FAIR VALUE MEASUREMENTS	Dec. 31, 2013
FAIR VALUE MEASUREMENTS	'
FAIR VALUE MEASUREMENTS	'

	NOTE 2. FAIR VALUE MEASUREMENTS

	Fair value is defined as the price that would be received on sale of an asset or paid to transfer a liability (exit price) in an orderly transaction between market participants at the measurement date. The FASB has established a fair value hierarchy that distinguishes between (1) market participant assumptions developed based on market data obtained from independent sources (observable inputs) and (2) an entity's own assumptions about market participant assumptions developed based on the best information available in the circumstances (unobservable inputs). The fair value hierarchy consists of three broad levels, which gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3).

	The three levels of the fair value hierarchy under the guidance for fair value measurement are described below:


	Level 1	Inputs are unadjusted quoted prices in active markets for identical assets or liabilities. Pricing inputs are based upon quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. For securities, the valuations are based on quoted prices of the security that are readily and regularly available in an active market, and accordingly, a significant degree of judgment is not required. As of December 31, 2013, and 2012, the Company used Level 1 assumptions for its money market funds.
	Level 2	Pricing inputs are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market or can be corroborated by observable market data for substantially the full term of the assets or liabilities. As of December 31, 2013, and 2012, the Company did not have any Level 2 financial assets or liabilities.


	Level 3	Pricing inputs are generally unobservable for the assets or liabilities and include situations where there is little, if any, market activity for the investment. The inputs into the determination of fair value require management's judgment or estimation of assumptions that market participants would use in pricing the assets or liabilities. The fair values are therefore determined using model-based techniques that include option pricing models, discounted cash flow models, and similar techniques. As of December 31, 2013, the Company did not have any Level 3 financial assets or liabilities. As of December 31, 2012, the Company used Level 3 assumptions for its convertible preferred stock warrant liability.

	The carrying amounts of cash equivalents, accounts receivable, prepaid expenses, accounts payable and accrued liabilities approximate fair value due to the short-term nature of these items. Based on the borrowing rates currently available to the Company for debt with similar terms, the carrying value of the capital lease, term debt and line of credit approximate fair value (using Level 2 inputs).

	Level 3 was used to value our convertible preferred stock warrant liability, the value of which is determined based on an option-pricing model that takes into account the contract terms as well as multiple inputs, such as the Company's stock price, risk-free interest rates and expected volatility. Additional quantitative information related to the convertible preferred stock warrants is included in Note 9.

	The following tables set forth the Company's financial instruments that were measured at fair value on a recurring basis as of December 31, 2013 and 2012, by level within the fair value hierarchy. The Company's assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability. The Company's fair value hierarchy for its financial assets and financial liabilities that are carried at fair value are as follows (in thousands):


	December 31, 2013	Fair Value			Level 1		Level 2		Level 3
	Money market funds (included in cash and cash equivalents)	$	2,900		$	2,900	$	—	$	—







	December 31, 2012	Fair Value			Level 1		Level 2		Level 3
	Money market funds (included in cash and cash equivalents)	$	2,900		$	2,900	$	—	$	—


	Convertible preferred stock warrant liability	$	(2,741	)	$	—	$	—	$	(2,741	)



	Convertible Preferred Stock Warrant Liability—Warrants to purchase the Company's convertible preferred stock were classified as liabilities in the consolidated balance sheets as of December 31, 2012. The warrants were subject to remeasurement at each balance sheet date, and any change in fair value was recognized as a component of other income (expense) in the consolidated statements of operations.

	A reconciliation of the convertible preferred stock warrants measured and recorded at fair value on a recurring basis, using significant unobservable inputs (Level 3) is as follows (in thousands):


		Years Ended December 31,
		2013			2012		2011
	Balance at beginning of period	$	2,741		$	433	$	138
	Changes in fair value of warrants		4,740			2,308		295
	Conversion of warrants to common stock		(7,481	)		—		—


	Balance at end of period	$	—		$	2,741	$	433

CASH_AND_CASH_EQUIVALENTS

CASH AND CASH EQUIVALENTS	12 Months Ended
CASH AND CASH EQUIVALENTS	Dec. 31, 2013
CASH AND CASH EQUIVALENTS	'
CASH AND CASH EQUIVALENTS	'

	NOTE 3. CASH AND CASH EQUIVALENTS

	Cash and cash equivalents as of December 31, 2013 and 2012, consisted of the following (in thousands):


		December 31,
		2013		2012
	Cash and cash equivalents
	Cash	$	110,973	$	11,996
	Money market funds		2,900		2,900


	Total cash and cash equivalents	$	113,873	$	14,896

PROPERTY_EQUIPMENT_AND_SOFTWAR

PROPERTY, EQUIPMENT AND SOFTWARE, NET	12 Months Ended
PROPERTY, EQUIPMENT AND SOFTWARE, NET	Dec. 31, 2013
PROPERTY, EQUIPMENT AND SOFTWARE, NET	'
PROPERTY, EQUIPMENT AND SOFTWARE, NET	'

	NOTE 4. PROPERTY, EQUIPMENT AND SOFTWARE, NET

	Property, equipment and software, net as of December 31, 2013 and 2012, consisted of the following (in thousands):


		December 31,
		2013			2012
	Capitalized internal-use software costs	$	14,030		$	10,441
	Computer hardware and software		17,077			4,281
	Furniture and fixtures		1,735			816
	Leasehold improvements		815			656
	Construction in progress		3,622			1,126


	Total		37,279			17,320
	Accumulated depreciation and amortization		(11,485	)		(6,381	)


	Total property, equipment and software, net	$	25,794		$	10,939





	Total depreciation and amortization expense, excluding amortization of internal-use software costs, was $4.5 million, $1.3 million and $0.5 million for the years ended December 31, 2013, 2012 and 2011, respectively. Amortization expense of internal-use software costs was $3.4 million, $2.3 million and $1.5 million for the years ended December 31, 2013, 2012 and 2011, respectively. Refer to Note 6 for details of the Company's capital lease as of December 31, 2013. The Company held no capital leases as of December 31, 2012.

ACCRUED_AND_OTHER_CURRENT_LIAB

ACCRUED AND OTHER CURRENT LIABILITIES	12 Months Ended
ACCRUED AND OTHER CURRENT LIABILITIES	Dec. 31, 2013
ACCRUED AND OTHER CURRENT LIABILITIES	'
ACCRUED AND OTHER CURRENT LIABILITIES	'

	NOTE 5. ACCRUED AND OTHER CURRENT LIABILITIES

	Accrued and other current liabilities as of December 31, 2013 and 2012, consisted of the following (in thousands):


		December 31,
		2013		2012
	Payroll and related expenses	$	10,722	$	3,357
	Accrued vacation		2,220		991
	Professional services		650		268
	Accrued credit cards		774		122
	Early exercise of unvested stock options		1,107		451
	Employee stock purchase plan		1,427		—
	Other accrued expenses		4,684		997


	Total accrued and other current liabilities	$	21,584	$	6,186

CAPITAL_LEASES

CAPITAL LEASES	12 Months Ended
CAPITAL LEASES	Dec. 31, 2013
CAPITAL LEASES	'
CAPITAL LEASES	'

	NOTE 6. CAPITAL LEASES

	Property and equipment at December 31, 2013 and 2012 includes $0.6 million and $0, respectively, acquired under capital lease agreements of which the majority consists of computer hardware and software. There was no accumulated depreciation of property and equipment acquired under these capital leases at December 31, 2013 and 2012, respectively. The related depreciation will be included in depreciation expense.

	Approximate remaining future minimum lease payments under these non-cancelable capital leases as of December 31, 2013 were as follows (in thousands):


	Year ending December 31,	Future
	Year ending December 31,	Payments
	2014	$	223
	2015		223
	2016		205
	2017		—
	2018		—
	Thereafter		—


	Total minimum lease payments	$	651


	Less: amount representing interest and taxes		(36	)
	Less: current portion of minimum lease payments		(203	)


	Capital lease obligations, net of current portion	$	412

OTHER_INCOME_EXPENSENET

OTHER INCOME (EXPENSE)-NET	12 Months Ended
OTHER INCOME (EXPENSE)-NET	Dec. 31, 2013
OTHER INCOME (EXPENSE)-NET	'
OTHER INCOME (EXPENSE)-NET	'

	NOTE 7. OTHER INCOME (EXPENSE)—NET

	Other income (expense)—net for the years ended December 31, 2013, 2012, and 2011, consisted of the following (in thousands):


		December 31,
		2013			2012		2011
	Gain (loss) on foreign translation	$	(205	)	$	43	$	—
	Other non-operating income (loss), net		(103	)		92		33


	Total other income (expense)—net	$	(308	)	$	135	$	33

DEBT

DEBT	12 Months Ended
	Dec. 31, 2013
DEBT	'
DEBT	'

	NOTE 8. DEBT

	Line of Credit—In April 2010, the Company entered into a loan and security agreement, or the Comerica Agreement, with Comerica Bank, or Comerica, to establish a revolving line of credit for working capital purposes. The maximum amount available for borrowing under the revolving line of credit, as amended in June 2013, was not to exceed the lesser of $35.0 million or an amount equal to 85% of certain eligible accounts receivable. Eligible accounts excluded, among others, accounts that had aged over 120 days, and accounts in which 25% of the total account had aged over 120 days, and certain other accounts such as governmental, intercompany, employee and certain foreign accounts. The revolving line of credit had a maturity date of July 26, 2014 and could be repaid and redrawn at any time prior to the maturity date, at which time all advances and any accrued and unpaid interest were due and payable. Interest was charged at LIBOR, plus a 2.75% applicable margin, which equaled 2.99% as of December 31, 2012, respectively. As of December 31, 2013 and 2012, the Company had $0 and $1.9 million, respectively, outstanding under the revolving line of credit.

	Term Debt—In March 2012, the Company amended the Comerica Agreement to provide for growth capital advances of up to $3.0 million. The Comerica Agreement was further amended in February 2013 to increase the growth capital advances to up to $15.0 million. Growth capital advances could be drawn on before February 13, 2014 and were payable in equal monthly installments beginning on March 13, 2014 and continuing over a twenty-four month period ending on February 13, 2016 when the remaining principal and any accrued and unpaid interest would be due and payable. Interest on outstanding balances was charged at LIBOR, plus a 4.75% applicable margin, which equaled 4.99% as of December 31, 2012, respectively. As of December 31, 2012, the principal amount of $5.0 million, respectively, was outstanding under the loan.

	Venture Debt—In April 2010, the Company entered into a loan and security agreement with Venture Lending and Leasing, or the VLL Agreement, to provide for a growth capital loan of up to $1.0 million, which the Company drew in full concurrently upon entering into the VLL Agreement. The funds borrowed were used for general corporate purposes of the Company. The loan was payable in monthly installments of interest only for the first six months, and thereafter interest and principal was payable in 30 equal monthly installments. Interest accrued at a fixed rate of 13%. All receivables, equipment, fixtures, deposit accounts, investment property, and all other goods and personal property of the Company, whether tangible or intangible, were collateral on the loan. The Agreement contained certain conditions of default. As of December 31, 2012, the principal amount of $0.1 million was outstanding under the agreement.

	In March 2013, the Company repaid the VLL growth capital loan in full per the terms of the VLL Agreement, upon which VLL's security interest in the Company's collateral was released, and the agreement was terminated. As such, no amounts were outstanding under the VLL Agreement as of December 31, 2013.

	Loan Facility—On December 20, 2013, we entered into an Amended and Restated Revolving Credit and Term Loan Agreement, or the Loan Facility, with certain lenders, including Comerica Bank, as administrative agent for the lenders. The Loan Facility provides for an $80.0 million revolving credit facility, with a $5.0 million letter of credit subfacility and a $1.5 million swing line subfacility, and a $20.0 million secured term loan facility. The Loan Facility permits us, subject to certain requirements, to request an increase in the maximum revolving commitments under the Loan Facility by up to $25.0 million in additional revolving commitments. Revolving loans may be advanced under the Loan Facility in amounts up to the lesser of the $80.0 million maximum and a borrowing base equal to 85% of the value of our eligible accounts receivable. The borrowing base is subject to certain reserves and eligibility criteria. Comerica may also issue letters of credit under the subfacility up to $5.0 million, provided that the aggregate amount of advances outstanding under the revolving facility, the subfacility and the swing line facility do not exceed the lesser of the $80.0 million maximum and the borrowing base amount. If at any time the aggregate amounts outstanding under the revolving facility, the letter of credit subfacility and the swing line facility exceed the lesser of the $80.0 million maximum and the borrowing base then in effect, then we must make a prepayment in an amount sufficient to eliminate the excess. Term loans equal to $20.0 million were advanced to us under the term loan facility during December 2013. Loan proceeds may be used for general corporate purposes. We may prepay revolving loans and term loans under the Loan Facility in whole or in part at any time without premium or penalty, subject to certain conditions.

	Revolving loans bear interest, at our option, at (i) a base rate determined pursuant to the terms of the Loan Facility, plus a spread of 1.75% to 2.50%, or (ii) a LIBOR rate determined pursuant to the terms of the Loan Facility, plus a spread of 2.75% to 3.50%. Term loans bear interest, at our option, at (i) a base rate determined pursuant to the terms of the Loan Facility, plus a spread of 2.75% to 3.50%, or (ii) a LIBOR rate determined pursuant to the terms of the Loan Facility, plus a spread of 3.75% to 4.50%. In each case, the spread is based on the cash reflected on our balance sheet for the preceding fiscal quarter. The base rate is determined by taking the greatest of (i) the prime rate announced by Comerica, (ii) the federal funds rate plus 1.0% and (iii) the daily adjusting LIBOR rate plus 1.0%. Interest is due and payable quarterly in arrears for base rate loans. Interest is due and payable at the end of an interest period (or at each three month interval in the case of loans with interest periods greater than three months) for LIBOR rate loans. Term loans will be repaid in quarterly principal installments of approximately $1.3 million commencing in January 2015, with any remaining principal, together with all accrued and unpaid interest, due and payable on December 20, 2018. Principal, together with all accrued and unpaid interest, on the revolving loans are due and payable on December 20, 2016.

	We are required to maintain certain financial covenants under the Loan Facility, including the following:



	EBITDA. We are required to maintain specified quarterly EBITDA, which is defined for this purpose, with respect to any fiscal period as an amount equal to the sum of (i) consolidated net income (loss) in accordance with GAAP, after eliminating all extraordinary nonrecurring items of income, plus (ii) depreciation and amortization, income tax expense, total interest expense paid or accrued, non-cash stock-based compensation expense, costs and expenses from permitted acquisitions up to certain limits, costs and expenses in connection with the Loan Facility and any other expenses agreed with Comerica and the lenders less (iii) all extraordinary and non-recurring revenue and gains (including income tax benefits).

	Liquidity ratio. Under the Loan Facility, the ratio of (i) the sum of all cash on deposit with Comerica and certain other domestic financial institutions and the aggregate amount of all eligible accounts receivable to (ii) all indebtedness owing to the lender of the Loan Facility must be at least 1.10 to 1.00.

	The terms of the Loan Facility also require us to comply with certain non-financial covenants. As of December 31, 2013, we were in compliance with each of the financial and non-financial covenants.

	Covenants

	As of December 31, 2012, the Company was not in compliance with various financial and non-financial covenants under the April 2010 Comerica Loan and Security Agreement. However, the Company subsequently obtained a waiver for each of the covenant violations. As of December 31, 2012, the Company was in breach of the covenant under the VLL Agreement requiring submission of monthly consolidated financial statements within 30 days of month end. As of March 31, 2013, the VLL Agreement had been terminated upon repayment. Hence, a waiver was not required.

	Future Payments

	Future principal payments of long-term debt as of December 31, 2013 were as follows (in thousands):


	Year ending December 31,	Future
		Payments
	2014	$	—
	2015		5,000
	2016		5,000
	2017		5,000
	2018		5,000


	Total		20,000


	Less: current portion of long-term debt		—


	Long-term debt, net of current portion	$	20,000





	As of December 31, 2013, the $7.2 million balance outstanding under the revolving credit facility had a maturity date of December 20, 2016, and as the Company has the option to draw upon or repay at any time, the balance is shown as a current liability in the accompanying consolidated balance sheet.

STOCKHOLDERS_EQUITY_DEFICIT

STOCKHOLDERS' EQUITY (DEFICIT)	12 Months Ended
STOCKHOLDERS' EQUITY (DEFICIT)	Dec. 31, 2013
STOCKHOLDERS' EQUITY (DEFICIT)	'
STOCKHOLDERS' EQUITY (DEFICIT)	'

	NOTE 9. STOCKHOLDERS' EQUITY (DEFICIT)

	Initial Public Offering

	In September 2013, the Company completed its IPO in which 4,000,000 shares of common stock were sold by the Company and 600,000 shares of common stock were sold by selling stockholders. The public offering price of the shares sold in the IPO was $29.00 per share. The Company did not receive any proceeds from the sales of shares by the selling stockholders. The total gross proceeds from the offering to the Company were $116.0 million. After deducting underwriters' discounts and commissions and offering expenses, the aggregate net proceeds received by the Company totaled approximately $103.3 million. Immediately prior to the closing of the IPO, all shares of the Company's outstanding convertible preferred stock automatically converted into 19,478,932 shares of common stock.

	The following table presents the shares authorized and issued and outstanding as of the periods presented (in thousands, except share data):


			December 31, 2013						December 31, 2012
			Shares			Shares			Shares			Shares		Liquidation
			Authorized			Issued and			Authorized			Issued and		Preference
						Outstanding						Outstanding
	Series A convertible preferred stock			—			—			10,884,902			10,618,372	$	9,860
	Series B convertible preferred stock			—			—			4,811,855			4,811,855		12,500
	Series C convertible preferred stock			—			—			1,116,030			1,116,030		8,187
	Series C-1 convertible preferred stock			—			—			2,975,228			2,932,675		34,500
	Common stock, $0.001 par value			1,000,000,000			32,825,992			35,850,100			8,680,041		—
	Undesignated preferred stock			100,000,000			—			—			—		—

	Warrants—In April 2010, the Company issued a fully vested warrant to purchase 161,533 shares of Series A preferred stock at an exercise price of $0.9286 per share. The warrant was issued in connection with the Company entering into a loan and security agreement. The warrant expires 10 years from the date of issuance. The fair value of the warrant at issuance was $22,000 based on the Company's option-pricing model, which approximates a binomial lattice model, using the weighted-average assumptions of 0% dividend yield, 70.5% volatility, risk-free interest rate of 3.96% and contractual life of 10 years. The warrant was outstanding as of December 31, 2012.

	On September 25, 2013, upon closing of the Company's IPO, the warrant converted from a warrant to purchase Series A preferred stock to common stock, and the liability at its then fair value of $4.5 million was reclassified to additional paid-in capital. Prior to this date, all changes in the fair value of the warrant were recorded in other income (expense) in the accompanying consolidated statements of operations.

	In April 2010, the Company issued a fully vested warrant to purchase 104,997 shares of Series A convertible preferred stock at an exercise price of $0.9286 per share. The warrant was issued in connection with the Company obtaining a line of credit. The warrant was to expire seven years from the date of issuance. The fair value of the warrant at issuance was $10,000 based on the Company's option-pricing model, which approximates a binomial lattice model, using the weighted-average assumptions of 0% dividend yield, 70.5% volatility, risk-free interest rate of 3.33% and contractual life of seven years. The warrant was outstanding as of December 31, 2012.

	On September 25, 2013, upon closing of the Company's IPO, the warrant converted from a warrant to purchase Series A preferred stock to a warrant to purchase shares of common stock and the liability at its then fair value of $2.9 million was reclassified to additional paid-in capital. Prior to this date, all changes in the fair value of the warrant were recorded in other income (expense) in the accompanying consolidated statements of operations.

	On September 25, 2013, following the closing of the IPO, the warrant to purchase common stock was exercised, resulting in the issuance of 104,997 shares of the Company's common stock.

	As of December 31, 2013, no warrants were outstanding. A reconciliation of the convertible preferred stock warrants measured and recorded at fair value can be found in Note 2.

	Reserved Shares of Common Stock—The Company's shares of capital stock reserved for issuance as of December 31, 2013 were as follows:


			December 31,
			2013
	Options outstanding			7,410,588
	Restricted stock units outstanding			382,402
	Available for future stock option and restricted stock unit grants			4,611,269
	Available for future employee stock purchase plan			1,000,000


	Total shares reserved			13,404,259





	2008 Equity Incentive Plan—The 2008 Equity Incentive Plan (the "2008 Plan") provides for the grant of incentive stock options and nonqualified stock options. The compensation committee of the Board of Directors has the authority to approve the employees and non-employees to whom options are granted and determine the terms of each option, including (i) the number of shares of common stock subject to the option; (ii) when the option becomes exercisable; (iii) the option exercise price, which, in the case of incentive stock options, must be at least 100% of the fair market value of the common stock as of the date of grant; and (iv) the duration of the option (which, in the case of incentive stock options, may not exceed 10 years). Options granted under the 2008 Plan generally vest over four years and expire no later than 10 years from the date of grant. As of December 31, 2012 and 2011, 14,738 and 33,080 shares of common stock, respectively, were available for future grant under the 2008 Plan. The Company has terminated the 2008 Plan for future use and provided that no further equity awards are to be granted under the 2008 Plan. All outstanding awards under the 2008 Plan will continue to be governed by their existing terms.

	Under the terms of the 2008 Plan, employees may be granted rights to exercise unvested options. Upon termination of service, an employee's unvested shares may be repurchased by the Company at the original purchase price. As of December 31, 2013, 2012 and 2011, 315,579, 449,622 and 170,543 unvested shares, respectively, were subject to repurchase. During the years ended December 31, 2013, 2012 and 2011, the Company repurchased 5,834, 8,959 and 6,250 shares of unvested stock, respectively.

	2013 Equity Incentive Plan—The Company's board of directors adopted and the Company's stockholders approved a 2013 Equity Incentive Plan (the "2013 Plan"), and the 2013 Plan became effective September 18, 2013. The 2013 Plan permits the grant of incentive stock options, within the meaning of Section 422 of the Code, to the Company's employees and any parent and subsidiary corporations' employees, and for the grant of nonstatutory stock options, restricted stock, restricted stock units, stock appreciation rights, performance units and performance shares to the Company's employees, directors and consultants and the Company's parent and subsidiary corporations' employees and consultants.

	Under the 2013 Plan, a total of 5,000,000 shares of common stock have been reserved for issuance. In addition, the shares to be reserved for issuance under the 2013 Plan will also include shares subject to stock options or similar awards granted under the 2008 Plan that expire or terminate without having been exercised in full and shares issued pursuant to awards granted under the 2008 Plan that are forfeited to or repurchased by the Company (provided that the maximum number of shares that may be added to the 2013 Plan pursuant to this provision is 7,900,000 shares).

	The number of shares available for issuance under the 2013 Plan will also include an annual increase on the first day of each fiscal year beginning in 2014, equal to the least of (i) 4,000,000 shares; (ii) 5% of the outstanding shares of common stock as of the last day of the immediately preceding fiscal year; or (iii) such other amount as the Company's board of directors may determine.

	The compensation committee of the board of directors has the authority to approve the employees and other service providers to whom equity awards are granted and to determine the terms of each award, subject to the terms of the 2013 Plan. The compensation committee may determine the number of shares subject to an award, except that the 2013 Plan provides certain limits on the number of awards that may be granted to non-employee members of the board of directors under the 2013 Plan in any fiscal year. Options and stock appreciation rights granted under the 2013 Plan must have a per share exercise price equal to at least 100% of the fair market value of a shares of the common stock as of the date of grant and may not expire later than 10 years from the date of grant.

	The following tables summarize option award activity:


		Number of			Weighted-			Weighted-			Aggregate
		Shares			Average			Average			Intrinsic Value
		Outstanding			Exercise Price			Remaining			(in thousands)
								Contractual
								Life (Years)
Balance at January 1, 2011			1,797,283		$	0.2			9.2		$	135
Options granted (weighted average fair value of $0.75 per share)			1,799,350			0.92
Options exercised			(339,354	)		0.59
Options forfeited			(449,917	)		0.68


Balance at December 31, 2011			2,807,362		$	0.55			8.9		$	4,212
Options granted (weighted average fair value of $5.32 per share)			3,962,055			5.2
Options exercised			(747,658	)		1.02
Options forfeited			(189,054	)		1.64


Balance at December 31, 2012			5,832,705		$	3.65			9.1		$	44,073
Options granted (weighted average fair value of $10.47 per share)			2,251,848			14.51
Options exercised			(406,323	)		3.23
Options forfeited			(267,642	)		3.97


Balance at December 31, 2013			7,410,588		$	6.97			8.5		$	404,106





		Number of			Weighted-			Weighted-			Aggregate
		Shares			Average			Average			Intrinsic Value
		Outstanding			Exercise Price			Remaining			(in thousands)
								Contractual
								Life (Years)
Options vested and expected to vest—December 31, 2012			5,148,950		$	3.58			9		$	39,307
Options vested and exercisable—December 31, 2012			1,510,615		$	1.97			8.2		$	13,951
Options vested and expected to vest—December 31, 2013			6,789,538		$	6.75			8.4		$	371,699
Options vested and exercisable—December 31, 2013			2,796,556		$	3.08			7.8		$	163,338

Aggregate intrinsic value represents the difference between the Company's estimated fair value of its common stock and the exercise price of outstanding in-the-money options. The total intrinsic value of options exercised was approximately $11.9 million, $1.1 million and $0.1 million for the years ended December 31, 2013, 2012 and 2011 respectively.

A summary of options outstanding and vested as of December 31, 2013 is as follows:


		Options Outstanding						Options Vested and
		Options Outstanding						Exercisable
Exercise Prices		Number			Weighted-			Number			Weighted-
		Outstanding			Average Life			Vested and			Average Life
					(in Years)			Exercisable			(in Years)
$0.13			40,000			5			40,000			5
$0.16			538,816			6			512,612			6
$0.27			494,750			6.9			395,126			6.9
$1.07			1,130,951			7.8			632,230			7.7
$2.97			188,793			8.5			66,029			8.5
$3.55			186,000			8.6			64,524			8.6
$6.58			2,682,945			8.9			1,049,812			8.9
$11.21			1,168,083			9.2			34,723			9.2
$15.33			753,050			9.4			—			—
$20.05			151,700			9.6			1,500			9.6
$29.00			22,500			9.7			—			—
$48.78			26,000			9.9			—			—
$63.37			27,000			9.8			—			—


			7,410,588			8.5			2,796,556			7.8





Employee Stock-based Compensation—The fair value of options on the date of grant is estimated based on the Black-Scholes option-pricing model using the single-option award approach with the weighted-average assumptions set forth below. Expected term represents the period that the Company's stock-based awards are expected to be outstanding and is determined based on the simplified method. Volatility is estimated using comparable public company volatility for similar option terms. The risk-free interest rate is determined using a U.S. Treasury rate for the period that coincides with the expected term.

As the Company has never paid cash dividends, and at present, has no intention to pay cash dividends in the future, expected dividends are zero. Expected forfeitures are based on the Company's historical experience. The Company uses the straight-line method for expense recognition.

The assumptions used to value stock-based awards granted to employees were as follows:


		Year Ended December 31,
		2013		2012		2011
Expected term (years)		5.3 - 6.6		5.3 - 7.3		5.4 - 6.1
Volatility		53.8% - 64.9%		61.2% - 63.4%		56.1% - 66.7%
Risk-free interest rate		1.04% - 1.88%		0.7% - 1.21%		1.13% - 3.06%
Dividend yield		—		—		—

The following table summarizes the allocation of stock-based compensation and restricted stock expense for employees and non-employees in the accompanying consolidated statements of operations (in thousands):


		Years Ended December 31,
		2013			2012			2011
		(in thousands)
Cost of revenue		$	471		$	37		$	7
Research and development			2,308			734			8
Sales and marketing			4,482			1,100			66
General and administrative			3,581			1,450			83


Total*		$	10,842		$	3,321		$	164






*
The table above includes the impact of the issuance of restricted stock at fair value.

As of December 31, 2013, 2012 and 2011, unamortized stock-based compensation expense related to unvested common stock options was $21.7 million, $12.5 million and $0.7 million, respectively. The weighted-average period over which such stock-based compensation expense will be recognized is approximately 2.9 years.

Options to Non-employees—The Company did not grant any stock options to non-employees for the years ended December 31, 2012 or 2011. For the year ended December 31, 2013, the Company granted options to purchase a total of 8,500 shares of common stock to non-employees. The definition of an employee includes a non-employee director of the Company. Stock options granted to non-employees are recorded at their fair value on the measurement date. The measurement of stock-based compensation is subject to periodic adjustment as the underlying equity instruments vest. The fair value of options granted to consultants is expensed when vested.

The Company recorded stock-based compensation expense for options issued to non-employees under the 2008 Plan of approximately $0.1 million, $0.1 million and $0.0 million for the years ended December 31, 2013, 2012 and 2011, respectively. Options to non-employees of 8,900 and 12,400 were outstanding as of December 31, 2013 and 2012, respectively.

Restricted Stock—Pursuant to restricted stock purchase agreements, the Company issued a total of 13,571 and 68,815 shares for the year ended December 31, 2012 and 2011, respectively, and no shares for the year ended December 31, 2013, respectively.

Restricted Stock Units (RSUs)—During the year ended December 31, 2013, the Company granted 383,402 RSUs and 1,000 RSUs were cancelled. For the year ended December 31, 2013, the Company recognized stock-based compensation expense associated with the RSUs of $1.0 million. At December 31, 2013, unrecognized compensation expense related to the RSUs was $14.5 million. The unrecognized compensation expense will be amortized on a straight-line basis through 2017.

Employee Stock Purchase Plan

In August 2013, the Company's board of directors adopted and the stockholders approved the Company's 2013 Employee Stock Purchase Plan (the "ESPP"), which became effective upon adoption by the Company's board of directors. The ESPP allows eligible employees to purchase shares of the Company's common stock at a discount through payroll deductions of up to 15% of their eligible compensation, subject to any plan limitations. The offering periods generally start on the first trading day on or after June 1 and December 1 of each year and end on the first trading day on or before November 30 and May 31 approximately six months later. The administrator may, in its discretion, modify the terms of future offering periods. Due to the timing of the IPO, the first offering period started October 1, 2013 and will end on May 31, 2014. At the end of each offering period, employees are able to purchase shares at 85% of the lower of the fair market value of the Company's common stock on the first trading day of the offering period or on the last trading day of the offering period. There were no offerings of share purchase rights to employees under the Company's ESPP for the year ended December 31, 2013. At December 31, 2013, total compensation costs related to rights to purchase common shares under the ESPP but not yet vested were approximately $1.8 million, which will be recognized over the offering period.

The assumptions used to calculate our stock-based compensation for each stock purchase right granted under the ESPP were as follows:


		Year Ended
		December 31, 2013
Expected term (years)			0.67
Volatility			66.2	%
Risk-free interest rate			0.07	%
Dividend yield			—

NET_INCOME_LOSS_PER_SHARE

NET INCOME (LOSS) PER SHARE	12 Months Ended
NET INCOME (LOSS) PER SHARE	Dec. 31, 2013
NET INCOME (LOSS) PER SHARE	'
NET INCOME (LOSS) PER SHARE	'

	NOTE 10. NET INCOME (LOSS) PER SHARE

	The Company calculates its basic and diluted net income (loss) per share attributable to common stockholders in conformity with the two-class method required for companies with participating securities. Under the two-class method, in periods when the Company has net income, net income attributable to common stockholders is determined by allocating undistributed earnings, calculated as net income less current period convertible preferred stock non-cumulative dividends, between common stock and convertible preferred stock. In computing diluted net income attributable to common stockholders, undistributed earnings are re-allocated to reflect the potential impact of dilutive securities. The Company's basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period. The diluted net loss per share attributable to common stockholders is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. For purposes of this calculation, convertible preferred stock, options to purchase common stock and preferred stock warrants are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is antidilutive.

	Basic loss per share is calculated by dividing net loss by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase, and excludes any dilutive effects of employee stock-based awards and warrants. As the Company had net losses for the years ended December 31, 2013, 2012 and 2011, all potential common shares were determined to be anti-dilutive.

	The following table sets forth the computation of net loss per common share (in thousands, except per share amounts):


		Years Ended December 31,
		2013			2012			2011
	Net loss	$	(20,932	)	$	(10,343	)	$	(4,325	)
	Weighted-average shares used to compute basic and diluted net loss per share		15,177			8,024			7,600


	Basic and diluted net loss per share	$	(1.38	)	$	(1.29	)	$	(0.57	)





	The following securities were excluded from the calculation of diluted net loss per share attributable to common stockholders because their effect would have been anti-dilutive for the periods presented (in thousands):


		Years Ended December 31,
		2013			2012			2011
	Convertible preferred stock		—			19,479			16,546
	Employee stock options		7,409			5,830			2,797
	Shares subject to repurchase		316			—			—
	Restricted stock units (RSUs)		383			—			—
	Employee stock purchase plan		58			—			—
	Convertible preferred stock warrants		—			267			267


			8,166			25,576			19,610

INCOME_TAXES

INCOME TAXES	12 Months Ended
INCOME TAXES	Dec. 31, 2013
INCOME TAXES	'
INCOME TAXES	'

	NOTE 11. INCOME TAXES

	The Company accounts for income taxes in accordance with authoritative guidance, which requires the use of the asset and liability method. Under this method, deferred income tax assets and liabilities are determined based upon the difference between the consolidated financial statement carrying amounts and the tax basis of assets and liabilities and are measured using the enacted tax rate expected to apply to taxable income in the years in which the differences are expected to be reversed.

	The following table presents domestic and foreign components of income (loss) before income taxes for the periods presented (in thousands):


			Years Ended December 31,
			2013			2012			2011
	Domestic		$	(21,568	)	$	(10,637	)	$	(4,401	)
	International			921			378			104


	Total		$	(20,647	)	$	(10,259	)	$	(4,297	)





	The components of provision for income taxes were as follows (in thousands):


			Years Ended
			December 31,
			2013			2012			2011
	Current:
	Federal		$	—		$	—		$	—
	State			(4	)		11			2
	Foreign			289			73			26


	Total provision for income taxes		$	285		$	84		$	28





	The following table presents a reconciliation of the statutory federal rate and the Company's effective tax rate for the periods presented:


			Years Ended December 31,
			2013			2012			2011
	Tax benefit at federal statutory rate			34	%		34	%		34	%
	State income taxes, net of federal effect			0.01			(0.07	)		(0.04	)
	Foreign rate differential			0.12			0.54			0.04
	Change in valuation allowance			(28.42	)		(25.16	)		(35.29	)
	Meals and entertainment			(2.07	)		(1.98	)		(2.49	)
	Warrant liability			(7.81	)		(7.65	)		(1.68	)
	Research Credits			2.79			0			4.72
	Other			0			(0.50	)		0.01


	Total provision			(1.38	)%		(0.82	)%		(0.73	)%





	Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The following table presents the significant components of the Company's deferred tax assets and liabilities for the periods presented (in thousands):


			December 31,
		2013			2012
Deferred tax assets:
Tax credit carry-forwards		$	2,256		$	843
Net operating loss carry-forwards			13,118			8,377
Charitable Contributions			133			—
Accrued liabilities and allowances			5,421			2,292


Gross deferred tax asset			20,928			11,512
Valuation allowance			(15,762	)		(8,831	)


Net deferred tax assets			5,166			2,681


Deferred tax liability:
Depreciation and amortization			(5,166	)		(2,681	)


Gross deferred tax liability			(5,166	)		(2,681	)


Net deferred tax assets (liabilities)		$	—		$	—





A valuation allowance is provided for deferred tax assets where the recoverability of the assets is uncertain. The determination to provide a valuation allowance is dependent upon the assessment of whether it is more likely than not that sufficient future taxable income will be generated to utilize the deferred tax assets. Based on the weight of the available evidence, which includes the Company's historical operating losses, lack of taxable income and the accumulated deficit, the Company provided a full valuation allowance against the deferred tax assets resulting from the tax loss and credits carried forward. As of December 31, 2013, the Company had net operating loss carry-forwards of approximately $43.9 million for federal income taxes and $18.4 million for state income taxes. If not utilized, these carry-forwards will begin to expire in 2029 for both federal purposes and state purposes.

As of December 31, 2013, the Company had research and development credit carry-forwards of approximately $1.7 million and $1.7 million for federal and state income taxes, respectively. If not utilized, the federal carry-forwards will begin to expire in various amounts beginning in 2029. The state tax credit can be carried forward indefinitely.

A stock option exercise may result in a tax deduction prior to the actual realization of the related tax benefit because the Company has a net operating loss carry-forward. In that situation, a tax benefit and a credit to additional paid-in capital for the excess federal and California deduction of $(8.3) million and $(1.0) million would not be recognized until that deduction reduces taxes payable.

Internal Revenue Code Section 382 limits the use of net operating loss and tax credit carry-forwards in certain situations where changes occur in the stock ownership of a company. If the Company has a change of ownership, then utilization of the net operating loss and tax credit carry-forwards may be restricted.

On January 1, 2009, the Company adopted ASC 740-10 (formerly referred to as FASB Interpretation No. 48, Accounting for Uncertainty in Income Taxes—an interpretation of FASB Statement No. 109). ASC 740-10 requires that the tax effects of a position be recognized only if it is "more likely than not" to be sustained based solely on its technical merits as of the reporting date. The Company considers many factors when evaluating and estimating its tax positions and tax benefits, which may require periodic adjustments and which may not accurately anticipate actual outcomes.

With the adoption of ASC 740-10, companies are required to adjust their financial statements to reflect only those tax positions that are more likely than not to be sustained. Any necessary adjustment would be recorded directly to retained earnings and reported as a change in accounting principle as of the date of adoption. ASC 740-10 prescribes a comprehensive model for the financial statement recognition, measurement, presentation and disclosure of uncertain tax positions taken or expected to be taken in income tax returns. The implementation of ASC 740, did not result in any material changes to the liability for unrecognized tax benefits.

The table below provides a reconciliation of the beginning and ending amount of unrecognized tax benefits (excluding interest and penalties) for the years ended December 31, 2013, 2012 and 2011 (in thousands):


		December 31,
		2013			2012			2011
Unrecognized benefit—beginning of period		$	272		$	184		$	83
Gross increases—prior year tax positions			126			10			—
Gross increases—current year tax positions			271			78			101


Unrecognized benefit—end of period		$	669		$	272		$	184





The unrecognized tax benefits of $0.7 million as of December 31, 2013 would have no impact on the Company's effective tax rate if recognized.

At December 31, 2013, the Company had no cumulative interest and penalties related to the uncertain tax position.

The Company is currently unaware of any uncertain tax positions that could result in significant additional payments, accruals, or other material deviation in this estimate over the next twelve months.

The Company's tax returns remain open to examination as follows: U.S. federal, 2010 through 2013; U.S. states, generally 2009 through 2013; and United Kingdom, 2011 through 2013.

COMMITMENTS_AND_CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
COMMITMENTS AND CONTINGENCIES	Dec. 31, 2013
COMMITMENTS AND CONTINGENCIES	'
COMMITMENTS AND CONTINGENCIES	'

	NOTE 12. COMMITMENTS AND CONTINGENCIES

	Operating Leases—The Company has operating lease agreements for office space for administration, research and development and sales and marketing activities in the United States that expire at various dates, with the latest expiration date in 2024.

	The Company recognizes rent expense on a straight-line basis over the lease term and records the difference between cash rent payments and the recognition of rent expense as a deferred rent liability. Rent expense was $4.3 million, $1.6 million and $0.7 million for the years ended December 31, 2013, 2012 and 2011, respectively.

	Approximate remaining future minimum lease payments under these non-cancelable operating leases as of December 31, 2013 were as follows (in thousands):


	Year ending December 31,	Future Payments
	2014	$	4,934
	2015		11,506
	2016		12,730
	2017		12,204
	2018		10,881
	Thereafter		38,473


		$	90,728





	Letter of Credit—As of December 31, 2013, 2012 and 2011, the Company had irrevocable letters of credit outstanding in the amount of $3.4 million, $0.2 million and $0.1 million for the benefit of a landlord related to non-cancelable facilities leases. The letters of credit have an expiration date of February 2023.

	Indemnification Agreements—In the ordinary course of business, the Company may provide indemnifications of varying scope and terms to customers, vendors, lessors, business partners, and other parties with respect to certain matters, including, but not limited to, losses arising out of breach of such agreements, services to be provided by the Company or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with directors and certain officers and employees that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors, officers or employees. No demands have been made upon the Company to provide indemnification under such agreements, and thus there are no claims that the Company is aware of that could have a material effect on the Company's consolidated balance sheets, consolidated statements of operations, consolidated statements of comprehensive loss, or consolidated statements of cash flows.

	Legal Proceedings—We are not currently a party to any legal proceedings, litigation, or claims that could materially affect our business, results of operations, cash flows, or financial position. We may, from time to time, be party to litigation and subject to claims incident to the ordinary course of business. As our growth continues, we may become party to an increasing number of litigation matters and claims. The outcome of litigation and claims cannot be predicted with certainty, and the resolution of any future matters could materially affect our future financial position, results of operations or cash flows.

RETIREMENT_PLANS

RETIREMENT PLANS	12 Months Ended
RETIREMENT PLANS	Dec. 31, 2013
RETIREMENT PLANS	'
RETIREMENT PLANS	'

	NOTE 13. RETIREMENT PLANS

	The Company has established a 401(k) plan to provide tax deferred salary deductions for all eligible employees. Participants may make voluntary contributions to the 401(k) plan, limited by certain Internal Revenue Service restrictions. The Company is responsible for the administrative costs of the 401(k) plan. The Company does not match employee contributions.

SEGMENTS

SEGMENTS	12 Months Ended
SEGMENTS	Dec. 31, 2013
SEGMENTS	'
SEGMENTS	'

	NOTE 14. SEGMENTS

	The Company considers operating segments to be components of the Company's business for which separate financial information is available that is evaluated regularly by the Company's chief operating decision maker in deciding how to allocate resources and in assessing performance. The chief operating decision maker for the Company is the Chief Executive Officer. The Chief Executive Officer reviews financial information presented on a consolidated basis for purposes of allocating resources and evaluating financial performance. The Company has one business activity, and there are no segment managers who are held accountable for operations, operating results or plans for levels or components below the consolidated unit level. Accordingly, the Company has determined that it has a single operating and reportable segment. The following table summarizes total revenue generated through sales personnel located in the respective locations (in thousands):


		Years Ended December 31,
		2013		2012		2011
	North America	$	213,601	$	96,289	$	43,415
	All Other Countries		27,004		10,300		1,237


	Total revenue	$	240,605	$	106,589	$	44,652





	The following table summarizes total long-lived assets in the respective locations (in thousands):


		December 31,
		2013		2012
	North America	$	23,956	$	9,959
	All Other Countries		1,838		980


	Total long-lived assets	$	25,794	$	10,939





	During the years ended December 31, 2013, 2012 and 2011, no single customer represented more than 10% of revenue. As of December 31, 2013 no single customer represented more than 10% of accounts receivable. As of December 31, 2012, one customer accounted for more than 10% of accounts receivable.

SUBSEQUENT_EVENTS

SUBSEQUENT EVENTS	12 Months Ended
SUBSEQUENT EVENTS	Dec. 31, 2013
SUBSEQUENT EVENTS	'
SUBSEQUENT EVENTS	'

	NOTE 15. SUBSEQUENT EVENTS

	In February 2014, the Company completed the underwritten follow-on public offering of its common stock in which 2,000,000 shares of common stock were sold by the Company and 3,000,000 shares of common stock were sold by selling stockholders. The public offering price of the shares sold in the offering was $61.00 per share. The Company did not receive any proceeds from the sale of shares by the selling stockholders. The total gross proceeds from the offering to the Company were $122.0 million. After deducting underwriters' discounts and commissions, the aggregate net proceeds received by the Company totaled approximately $116.5 million.

NATURE_OF_BUSINESS_AND_SUMMARY1

NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2013
NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	'
Principles of Consolidation	'
	Principles of Consolidation—The consolidated financial statements include the Company and its wholly-owned subsidiary, Rocket Fuel, Ltd., an England and Wales corporation, which is engaged in marketing and selling advertising campaigns. All intercompany transactions and balances have been eliminated in consolidation.
Use of Estimates	'
	Use of Estimates—The preparation of consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.
Certain Significant Risks and Uncertainties	'
	Certain Significant Risks and Uncertainties—The Company is subject to those risks common in technology-driven markets, including, but not limited to, competitive forces, dependence on key personnel, customer demand for its solution, management of growth, the successful protection of its proprietary technologies, compliance with government regulations, and the possibility of not being able to obtain additional financing when needed.
Foreign Currency Translation	'

	Foreign Currency Translation—The Company's foreign subsidiary records its assets, liabilities and results of operations in its local currency, which is their functional currency. The Company translates its subsidiary consolidated financial statements into U.S. dollars each reporting period for purposes of consolidation.

	Assets and liabilities of the Company's foreign subsidiary are translated at the period-end currency exchange rates, certain equity accounts are translated at historical exchange rates while revenue, expenses, gains and losses are translated at the average currency exchange rates in effect for the period. The effects of these translation adjustments are reported in a separate component of stockholders' equity titled accumulated other comprehensive loss.

Fair Value of Financial Instruments	'
	Fair Value of Financial Instruments—The Company's financial instruments consist principally of cash equivalents, accounts receivable, accounts payable, accrued liabilities, capital lease, term debt and line of credit. The fair value of the Company's cash equivalents is determined based on quoted prices in active markets for identical assets for its money market funds. The recorded values of the Company's accounts receivable, accounts payable and accrued liabilities approximate their current fair values due to the relatively short-term nature of these accounts. The Company believes that the fair value of the capital lease, term debt and line of credit approximates its recorded amount at December 31, 2013 as the interest rate on the capital lease, term debt and line of credit is variable and is based on market interest rates after consideration of default and credit risk.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents—Cash consists of cash maintained in checking and savings accounts. All highly liquid investments purchased with an original maturity date of 90 days or less at the date of purchase are considered to be cash equivalents. Cash equivalents consist of money market funds.
Concentration of Credit Risk	'

	Concentration of Credit Risk—Financial instruments, which potentially subject the Company to significant concentrations of credit risk, consist primarily of cash and accounts receivable. A significant portion of the Company's cash is held at one major financial institution, which management assesses to be of high credit quality. The Company has not experienced any losses in such accounts.

	The Company mitigates its credit risk with respect to accounts receivable by performing credit evaluations and monitoring its customers' accounts receivable balances. As of December 31, 2013, no single customer accounted for more than 10% of accounts receivable. As of December 31, 2012, one customer accounted for more than 10% of accounts receivable.

	During the years ended December 31, 2013, 2012 and 2011, no single customer represented more than 10% of revenue.

Provision for Doubtful Accounts	'

	Provision for Doubtful Accounts—The Company records a provision for doubtful accounts based on historical experience and a detailed assessment of the collectability of its accounts receivable. In estimating the allowance for doubtful accounts, management considers, among other factors, the aging of the accounts receivable, historical write-offs and the credit-worthiness of each customer. If circumstances change, such as higher-than-expected defaults or an unexpected material adverse change in a major customer's ability to meet its financial obligations, the Company's estimate of the recoverability of the amounts due could be reduced by a material amount.

	The following table presents the changes in the allowance for doubtful accounts (in thousands):


		Year Ended December 31,
		2013		2012			2011
	Allowance for doubtful accounts:
	Balance, beginning of period	$	468	$	203		$	—
	Add: bad debt expense		569		285			203
	Less: write-offs, net of recoveries		20		(20	)		—


	Balance, end of period	$	1,057	$	468		$	203




Property and Equipment	'

	Property and Equipment—Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization is computed using the straight-line method over the estimated useful lives of the related assets. Maintenance and repairs are charged to expense as incurred, and improvements and betterments are capitalized. When assets are retired or otherwise disposed of, the cost and accumulated depreciation or amortization, as applicable, are removed from the balance sheet and any resulting gain or loss is reflected in operations in the period realized.

	Construction in progress primarily includes costs related to the leasehold improvements associated with our new corporate headquarters in Redwood City, California and the recently leased New York, New York sales office. Construction in progress also includes network equipment infrastructure to support our data centers around the world. Interest capitalized during the periods presented was not material.

	Leasehold improvements are amortized on a straight-line basis over the term of the lease, or the useful life of the assets, whichever is shorter. Depreciation and amortization periods for the Company's property and equipment are as follows:


	Asset Classification	Estimated Useful Life
	Computer hardware and purchased software	2 - 3 years
	Capitalized internal-use software costs	2 - 3 years
	Office equipment, furniture and fixtures	5 years
Internal Use Software Development Costs	'

	Internal-Use Software Development Costs—The Company incurs costs to develop software for internal use. The Company expenses all costs that relate to the planning and post implementation phases of development as research and development expense. The Company capitalizes costs when preliminary efforts are successfully completed, management has authorized and committed project funding, and it is probable that the project will be completed and will be used as intended. Costs incurred for enhancements that are expected to result in additional material functionality are capitalized. The Company capitalized $6.3 million, $4.7 million and $2.6 million in internal-use software costs during the years ended December 31, 2013, 2012 and 2011, respectively, which are included in property, equipment and software—net on the consolidated balance sheets.

	Amortization commences when the website or software for internal use is ready for its intended use and the amortization period is the estimated useful life of the related asset, which is generally three years. Amortization expense totaled $3.4 million, $2.3 million and $1.5 million for the years ended December 31, 2013, 2012 and 2011, respectively.

Impairment of Long-lived Asset	'
	Impairment of Long-lived Assets—The Company periodically reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset is impaired or the estimated useful lives are no longer appropriate. If indicators of impairment exist and the undiscounted projected cash flows associated with such assets are less than the carrying amount of the asset, an impairment loss is recorded to write the assets down to their estimated fair values. Fair value is estimated based on discounted future cash flows. No impairment charges were recorded during the years ended December 31, 2013, 2012 and 2011.
Revenue Recognition	'

	Revenue Recognition—The company generates revenue by delivering digital advertisements to Internet users through various channels, including display, mobile, social and video.

	The Company recognizes revenue when all four of the following criteria are met:



	•
	Persuasive evidence of an arrangement exists

	•
	Delivery has occurred or a service has been provided

	•
	Customer fees are fixed or determinable

	•
	Collection is reasonably assured

	Revenue arrangements are evidenced by a fully executed insertion order ("IO"). Generally, IOs state the number and type of advertising impressions (cost-per-thousand) to be delivered, the agreed upon rate for each delivered impression, and a fixed period of time for delivery.

	The Company determines collectability by performing ongoing credit evaluations and monitoring its customers' accounts receivable balances. For new customers and their agents, which may be advertising agencies or other third parties, the Company performs a credit check with an independent credit agency and may check credit references to determine creditworthiness. The Company only recognizes revenue when collection is reasonably assured.

	In the normal course of business, the Company frequently contracts with advertising agencies on behalf of their advertiser clients. The determination of whether revenue should be reported on a gross or net basis is based on an assessment of whether the Company is acting as the principal or an agent in the transaction. In determining whether the Company acts as the principal or an agent, the Company follows the accounting guidance for principal-agent considerations. While none of the factors identified in this guidance is individually considered presumptive or determinative, because the Company is the primary obligor and is responsible for (i) fulfilling the advertisement delivery, (ii) establishing the selling prices for delivery of the advertisements, and (iii) performing all billing and collection activities including retaining credit risk, the Company has concluded that it acts as the principal in the majority of these arrangements and therefore reports revenue earned and costs incurred on a gross basis.

	On occasion, the Company has offered customer incentive programs which provide rebates after achieving a specified level of advertising spending. The Company records reductions to revenue for estimated commitments related to these customer incentive programs. For transactions involving incentives, the Company recognizes revenue net of the estimated amount to be paid by rebate, provided that the rebate amount can be reasonably and reliably estimated and the other conditions for revenue recognition have been met. The Company's policy requires that, if rebates cannot be reliably estimated, revenue is not recognized until reliable estimates can be made or the rebate program lapses.

Multiple-Element Arrangements	'

	Multiple-Element Arrangements—The Company enters into arrangements to sell advertising that includes different media placements or ad services that are delivered at the same time, or within close proximity of one another. Beginning on January 1, 2011, the Company adopted new authoritative guidance on multiple element arrangements, using the prospective method for all arrangements entered into or materially modified from the date of adoption. Under this new guidance, the Company allocates arrangement consideration in multiple-deliverable revenue arrangements at the inception of an arrangement to all deliverables or those packages in which all components of the package are delivered at the same time, based on the relative selling price method in accordance with the selling price hierarchy, which includes: (1) vendor-specific objective evidence ("VSOE"), if available; (2) third-party evidence ("TPE"), if VSOE is not available; and (3) best estimate of selling price ("BESP"), if neither VSOE nor TPE is available.

	VSOE—The Company determines VSOE based on its historical pricing and discounting practices for the specific product or service when sold separately. In determining VSOE, the Company requires that a substantial majority of the stand-alone selling prices for these services fall within a reasonably narrow pricing range. The Company has not been able to establish VSOE for any of its advertising offerings.

	TPE—When VSOE cannot be established for deliverables in multiple element arrangements, the Company applies judgment with respect to whether it can establish a selling price based on TPE. TPE is determined based on competitor prices for similar deliverables when sold separately. Generally, the Company's go-to-market strategy differs from that of its peers and its offerings contain a significant level of differentiation such that the comparable pricing of services cannot be obtained. Furthermore, the Company is unable to reliably determine the selling prices of similar competitor services on a stand-alone basis. As a result, the Company has not been able to establish selling price based on TPE.

	BESP—When it is unable to establish selling price using VSOE or TPE, the Company uses BESP in its allocation of arrangement consideration. The objective of BESP is to determine the price at which the Company would transact a sale if the service were sold on a stand-alone basis. BESP is generally used to allocate the selling price to deliverables in the Company's multiple element arrangements. The Company determines BESP for deliverables by considering multiple factors, including, but not limited to, prices it charges for similar offerings, market conditions, competitive landscape and pricing practices. In particular, the Company reviews multiple data points to determine BESP, including price lists used by the Company's sales team in pricing negotiations, historical average and median pricing achieved in prior contractual customer arrangements and input from the Company's sales operation department regarding what it believes the deliverables could be sold for on a stand-alone basis. BESP is determined at an advertising unit level that is consistent with the Company's underlying market strategy and stratified based on specific consideration of channel, geography, industry and size, as deemed necessary.

	The Company limits the amount of allocable arrangement consideration to amounts that are fixed or determinable and that are not contingent on future performance or future deliverables. The Company will regularly review BESP. Changes in assumptions or judgments or changes to the elements in the arrangement could cause a material increase or decrease in the amount of revenue that the Company reports in a particular period.

	The Company recognizes the relative fair value of advertising services as they are delivered, assuming all other revenue recognition criteria are met. Deferred revenue is comprised of contractual billings in excess of recognized revenue and payments received in advance of revenue recognition.

Cost of Revenue	'
	Cost of Revenue—Cost of revenue consists primarily of media cost for advertising impressions purchased from real-time advertising exchanges and other third parties. Cost of revenue also includes third-party data center costs and the salaries and related costs of the Company's operations group. This group sets up, initiates and monitors the Company's advertising campaigns. In addition, depreciation of the data center equipment, rental payments to third-party vendors for data centers and amortization of capitalized internal-use software are included in cost of revenue.
Research and Development	'
	Research and Development—Research and development expenses include costs associated with the maintenance and ongoing development of the Company's technology, including compensation and employee benefits and allocated costs associated with the Company's engineering and research and development departments, as well as costs for contracted services and supplies. Allocated costs include charges for facilities, office expenses, telephones, and other miscellaneous expenses. The Company reviews costs incurred in the application development stage and assesses such costs for potential capitalization.
Sales and Marketing	'
	Sales and Marketing—Sales and marketing expenses consist primarily of compensation (including commissions) and employee benefits of sales and marketing personnel and related support teams, allocated costs, certain advertising costs, travel, trade shows and marketing materials. Allocated costs include charges for facilities, office expenses, telephones, and other miscellaneous expenses. The Company incurred advertising costs of $3.6 million, $0.1 million and $0.1 million for the years ended December 31, 2013, 2012 and 2011, respectively.
General and Administrative	'
	General and Administrative—General and administrative expenses include facilities costs, executive and administrative compensation and employee benefits, depreciation, professional services fees, insurance costs, bad debt and other allocated costs, such as facility-related expenses, supplies and other fixed costs. Allocated costs include charges for facilities, office expenses, telephones, and other miscellaneous expenses.
Stock-Based Compensation	'

	Stock-based Compensation—The Company measures compensation expense for all stock-based payment awards, including stock options granted to employees, based on the estimated fair values on the date of the grant. The fair value of each stock option granted is estimated using the Black-Scholes option pricing model. Stock-based compensation is recognized on a straight-line basis over the requisite vesting period, net of estimated forfeitures. The forfeiture rate is based on an analysis of the Company's actual historical forfeitures.

	The Company accounts for stock options issued to non-employees based on the fair value of the awards determined using the Black-Scholes option pricing model. The fair value of stock options granted to non-employees is re-measured as the stock options vest, and the resulting change in fair value, if any, is recognized in the Company's consolidated statement of operations during the period the related services are rendered, generally between one and four years.

Preferred Stock Warrant Liability	'
	Preferred Stock Warrant Liability—Freestanding warrants related to shares that are redeemable or contingently redeemable are classified as a liability on the Company's consolidated balance sheets. The fully vested convertible preferred stock warrants were subject to re-measurement at each balance sheet date, and any change in fair value is recognized as a component of other expense, net. As completion of the Company's initial public offering constituted a liquidation event, the convertible preferred stock warrants were converted into common stock or warrants to purchase common stock, and the liability was reclassified to additional paid-in capital as of December 31, 2013.
Income Taxes	'

	Income Taxes—The Company accounts for income taxes using an asset and liability approach. Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Operating loss and tax credit carry-forwards are measured by applying currently enacted tax laws. Valuation allowances are provided when necessary to reduce net deferred tax assets to an amount that is more likely than not to be realized. Due to uncertainty as to the realization of benefits from deferred tax assets, including net operating loss carry-forwards, research and development and other tax credits, the Company has provided a full valuation allowance reserved against such assets as of December 31, 2013, 2012 and 2011.

	The Company recognizes the tax effects of an uncertain tax position only if it is more likely than not to be sustained based solely on its technical merits as of the reporting date, and then, only in an amount more likely than not to be sustained upon review by the tax authorities. The Company considers many factors when evaluating and estimating its tax positions and tax benefits, which may require periodic adjustments and which may not accurately anticipate actual outcomes.

Comprehensive Income (Loss)	'
	Comprehensive Income (Loss)—In June 2011, the Financial Accounting Standards Board ("FASB") issued an accounting standards update that requires an entity to present the total of comprehensive income, the components of net income and the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements. This guidance eliminates the option to present the components of other comprehensive income as part of the statement of equity. The Company retrospectively adopted these new standards in the first quarter of 2012 and has presented a separate consolidated statement of comprehensive loss for the years ended December 31, 2013, 2012 and 2011.
Deferred Offering Costs	'
	Deferred Offering Costs—Deferred offering costs consisted primarily of direct incremental costs related to the Company's initial public offering of its common stock. Approximately $0.1 million of deferred offering costs are included in other assets on the Company's consolidated balance sheets as of December 31, 2013 and 2012, respectively. Upon completion of the initial public offering, these amounts were offset against the proceeds of the offering.
Recently Issued and Adopted Accounting Pronouncements	'

	Recently Issued and Adopted Accounting Pronouncements—Under the Jumpstart Our Business Startups Act, or JOBS Act, we qualify as an "emerging growth company." We have irrevocably elected to opt out of the extended transition period for complying with new or revised accounting standards pursuant to Section 107(b) of the JOBS Act, and, therefore, we will be subject to the same new or revised accounting standards as other public companies that are not "emerging growth companies."

	In February 2013, the FASB issued guidance that addresses the presentation of amounts reclassified from accumulated other comprehensive income. This guidance does not change current financial reporting requirements. Instead, an entity is required to cross-reference to other required disclosures that provide additional detail about amounts reclassified out of accumulated other comprehensive income. In addition, the guidance requires an entity to present significant amounts reclassified out of accumulated other comprehensive income by line item of net income if the amount reclassified is required to be reclassified to net income in its entirety in the same reporting period. Adoption of this standard is required for periods beginning after December 15, 2012 for public companies. The adoption of this accounting standard did not have an impact on our consolidated financial position, results of operations and cash flows.

	In July 2013, the Financial Accounting Standards Board issued Accounting Standards Update (ASU) No. 2013-11, Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (ASU 2013-11). The guidance requires an entity to present its unrecognized tax benefits net of its deferred tax assets when settlement in this manner is available under the tax law, which would be based on facts and circumstances as of the balance sheet reporting date and would not consider future events. Gross presentation of unrecognized tax benefit will still be required in the notes to the financial statements. ASU 2013-11 will apply on a prospective basis to all unrecognized tax benefits that exist at the effective date. This ASU is effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. The adoption of ASU 2013-11 is not expected to have a material impact on our consolidated financial statements.

NATURE_OF_BUSINESS_AND_SUMMARY2

NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2013
NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	'
Schedule of changes in the allowance for doubtful accounts	'

	The following table presents the changes in the allowance for doubtful accounts (in thousands):


		Year Ended December 31,
		2013		2012			2011
	Allowance for doubtful accounts:
	Balance, beginning of period	$	468	$	203		$	—
	Add: bad debt expense		569		285			203
	Less: write-offs, net of recoveries		20		(20	)		—


	Balance, end of period	$	1,057	$	468		$	203




Schedule of depreciation and amortization periods for the Company's property and equipment	'




	Asset Classification	Estimated Useful Life
	Computer hardware and purchased software	2 - 3 years
	Capitalized internal-use software costs	2 - 3 years
	Office equipment, furniture and fixtures	5 years

FAIR_VALUE_MEASUREMENTS_Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
FAIR VALUE MEASUREMENTS (Tables)	Dec. 31, 2013
FAIR VALUE MEASUREMENTS	'
Schedule of Company's fair value hierarchy for its financial assets and financial liabilities that are carried at fair value	'

	The Company's fair value hierarchy for its financial assets and financial liabilities that are carried at fair value are as follows (in thousands):


	December 31, 2013	Fair Value			Level 1		Level 2		Level 3
	Money market funds (included in cash and cash equivalents)	$	2,900		$	2,900	$	—	$	—







	December 31, 2012	Fair Value			Level 1		Level 2		Level 3
	Money market funds (included in cash and cash equivalents)	$	2,900		$	2,900	$	—	$	—


	Convertible preferred stock warrant liability	$	(2,741	)	$	—	$	—	$	(2,741	)


Schedule of reconciliation of the convertible preferred stock warrants measured and recorded at fair value on a recurring basis, using significant unobservable inputs (Level 3)	'

	A reconciliation of the convertible preferred stock warrants measured and recorded at fair value on a recurring basis, using significant unobservable inputs (Level 3) is as follows (in thousands):


		Years Ended December 31,
		2013			2012		2011
	Balance at beginning of period	$	2,741		$	433	$	138
	Changes in fair value of warrants		4,740			2,308		295
	Conversion of warrants to common stock		(7,481	)		—		—


	Balance at end of period	$	—		$	2,741	$	433

CASH_AND_CASH_EQUIVALENTS_Tabl

CASH AND CASH EQUIVALENTS (Tables)	12 Months Ended
CASH AND CASH EQUIVALENTS (Tables)	Dec. 31, 2013
CASH AND CASH EQUIVALENTS	'
Schedule of cash and cash equivalents	'

	Cash and cash equivalents as of December 31, 2013 and 2012, consisted of the following (in thousands):


		December 31,
		2013		2012
	Cash and cash equivalents
	Cash	$	110,973	$	11,996
	Money market funds		2,900		2,900


	Total cash and cash equivalents	$	113,873	$	14,896

PROPERTY_EQUIPMENT_AND_SOFTWAR1

PROPERTY, EQUIPMENT AND SOFTWARE, NET (Tables)	12 Months Ended
PROPERTY, EQUIPMENT AND SOFTWARE, NET (Tables)	Dec. 31, 2013
PROPERTY, EQUIPMENT AND SOFTWARE, NET	'
Schedule of property, equipment and software	'

	Property, equipment and software, net as of December 31, 2013 and 2012, consisted of the following (in thousands):


		December 31,
		2013			2012
	Capitalized internal-use software costs	$	14,030		$	10,441
	Computer hardware and software		17,077			4,281
	Furniture and fixtures		1,735			816
	Leasehold improvements		815			656
	Construction in progress		3,622			1,126


	Total		37,279			17,320
	Accumulated depreciation and amortization		(11,485	)		(6,381	)


	Total property, equipment and software, net	$	25,794		$	10,939

ACCRUED_AND_OTHER_CURRENT_LIAB1

ACCRUED AND OTHER CURRENT LIABILITIES (Tables)	12 Months Ended
ACCRUED AND OTHER CURRENT LIABILITIES (Tables)	Dec. 31, 2013
ACCRUED AND OTHER CURRENT LIABILITIES	'
Schedule of accrued and other current liabilities	'

	Accrued and other current liabilities as of December 31, 2013 and 2012, consisted of the following (in thousands):


		December 31,
		2013		2012
	Payroll and related expenses	$	10,722	$	3,357
	Accrued vacation		2,220		991
	Professional services		650		268
	Accrued credit cards		774		122
	Early exercise of unvested stock options		1,107		451
	Employee stock purchase plan		1,427		—
	Other accrued expenses		4,684		997


	Total accrued and other current liabilities	$	21,584	$	6,186

CAPITAL_LEASES_Tables

CAPITAL LEASES (Tables)	12 Months Ended
CAPITAL LEASES (Tables)	Dec. 31, 2013
CAPITAL LEASES	'
Schedule of approximate remaining future minimum lease payments under non-cancelable capital leases	'

	Approximate remaining future minimum lease payments under these non-cancelable capital leases as of December 31, 2013 were as follows (in thousands):


	Year ending December 31,	Future
	Year ending December 31,	Payments
	2014	$	223
	2015		223
	2016		205
	2017		—
	2018		—
	Thereafter		—


	Total minimum lease payments	$	651


	Less: amount representing interest and taxes		(36	)
	Less: current portion of minimum lease payments		(203	)


	Capital lease obligations, net of current portion	$	412

OTHER_INCOME_EXPENSENET_Tables

OTHER INCOME (EXPENSE)-NET (Tables)	12 Months Ended
OTHER INCOME (EXPENSE)-NET (Tables)	Dec. 31, 2013
OTHER INCOME (EXPENSE)-NET	'
Schedule of other income (expense), net	'

	Other income (expense)—net for the years ended December 31, 2013, 2012, and 2011, consisted of the following (in thousands):


		December 31,
		2013			2012		2011
	Gain (loss) on foreign translation	$	(205	)	$	43	$	—
	Other non-operating income (loss), net		(103	)		92		33


	Total other income (expense)—net	$	(308	)	$	135	$	33

DEBT_Tables

DEBT (Tables)	12 Months Ended
DEBT (Tables)	Dec. 31, 2013
DEBT	'
Schedule of future principal payments of long-term debt	'

	Future principal payments of long-term debt as of December 31, 2013 were as follows (in thousands):


	Year ending December 31,	Future
	Year ending December 31,	Payments
	2014	$	—
	2015		5,000
	2016		5,000
	2017		5,000
	2018		5,000


	Total		20,000


	Less: current portion of long-term debt		—


	Long-term debt, net of current portion	$	20,000

STOCKHOLDERS_EQUITY_DEFICIT_Ta

STOCKHOLDERS' EQUITY (DEFICIT) (Tables)	12 Months Ended
STOCKHOLDERS' EQUITY (DEFICIT) (Tables)	Dec. 31, 2013
STOCKHOLDERS' EQUITY (DEFICIT)	'
Schedule of shares authorized and issued and outstanding	'

	The following table presents the shares authorized and issued and outstanding as of the periods presented (in thousands, except share data):


		December 31, 2013					December 31, 2012
		Shares			Shares		Shares		Shares		Liquidation
		Authorized			Issued and		Authorized		Issued and		Preference
					Outstanding				Outstanding
	Series A convertible preferred stock		—			—		10,884,902		10,618,372	$	9,860
	Series B convertible preferred stock		—			—		4,811,855		4,811,855		12,500
	Series C convertible preferred stock		—			—		1,116,030		1,116,030		8,187
	Series C-1 convertible preferred stock		—			—		2,975,228		2,932,675		34,500
	Common stock, $0.001 par value		1,000,000,000			32,825,992		35,850,100		8,680,041		—
	Undesignated preferred stock		100,000,000			—		—		—		—
Schedule of shares of common stock reserved for issuance	'




		December 31,
		2013
	Options outstanding		7,410,588
	Restricted stock units outstanding		382,402
	Available for future stock option and restricted stock unit grants		4,611,269
	Available for future employee stock purchase plan		1,000,000


	Total shares reserved		13,404,259




Summary of option award activity	'




		Number of			Weighted-		Weighted-		Aggregate
		Shares			Average		Average		Intrinsic Value
		Outstanding			Exercise Price		Remaining		(in thousands)
							Contractual
							Life (Years)
	Balance at January 1, 2011		1,797,283		$	0.2		9.2	$	135
	Options granted (weighted average fair value of $0.75 per share)		1,799,350			0.92
	Options exercised		(339,354	)		0.59
	Options forfeited		(449,917	)		0.68


	Balance at December 31, 2011		2,807,362		$	0.55		8.9	$	4,212
	Options granted (weighted average fair value of $5.32 per share)		3,962,055			5.2
	Options exercised		(747,658	)		1.02
	Options forfeited		(189,054	)		1.64


	Balance at December 31, 2012		5,832,705		$	3.65		9.1	$	44,073
	Options granted (weighted average fair value of $10.47 per share)		2,251,848			14.51
	Options exercised		(406,323	)		3.23
	Options forfeited		(267,642	)		3.97


	Balance at December 31, 2013		7,410,588		$	6.97		8.5	$	404,106





		Number of			Weighted-		Weighted-		Aggregate
		Shares			Average		Average		Intrinsic Value
		Outstanding			Exercise Price		Remaining		(in thousands)
							Contractual
							Life (Years)
	Options vested and expected to vest—December 31, 2012		5,148,950		$	3.58		9	$	39,307
	Options vested and exercisable—December 31, 2012		1,510,615		$	1.97		8.2	$	13,951
	Options vested and expected to vest—December 31, 2013		6,789,538		$	6.75		8.4	$	371,699
	Options vested and exercisable—December 31, 2013		2,796,556		$	3.08		7.8	$	163,338
Summary of options outstanding and vested	'




		Options Outstanding					Options Vested and
		Options Outstanding					Exercisable
	Exercise Prices	Number			Weighted-		Number		Weighted-
		Outstanding			Average Life		Vested and		Average Life
					(in Years)		Exercisable		(in Years)
	$0.13		40,000			5		40,000		5
	$0.16		538,816			6		512,612		6
	$0.27		494,750			6.9		395,126		6.9
	$1.07		1,130,951			7.8		632,230		7.7
	$2.97		188,793			8.5		66,029		8.5
	$3.55		186,000			8.6		64,524		8.6
	$6.58		2,682,945			8.9		1,049,812		8.9
	$11.21		1,168,083			9.2		34,723		9.2
	$15.33		753,050			9.4		—		—
	$20.05		151,700			9.6		1,500		9.6
	$29.00		22,500			9.7		—		—
	$48.78		26,000			9.9		—		—
	$63.37		27,000			9.8		—		—


			7,410,588			8.5		2,796,556		7.8




Schedule of assumptions used to value stock-based awards granted to employees	'




		Year Ended December 31,
		2013		2012		2011
	Expected term (years)	5.3 - 6.6		5.3 - 7.3		5.4 - 6.1
	Volatility	53.8% - 64.9%		61.2% - 63.4%		56.1% - 66.7%
	Risk-free interest rate	1.04% - 1.88%		0.7% - 1.21%		1.13% - 3.06%
	Dividend yield	—		—		—
Summary of allocation of stock-based compensation and restricted stock for employees and non-employees	'

	The following table summarizes the allocation of stock-based compensation and restricted stock expense for employees and non-employees in the accompanying consolidated statements of operations (in thousands):


		Years Ended December 31,
		2013			2012		2011
		(in thousands)
	Cost of revenue	$	471		$	37	$	7
	Research and development		2,308			734		8
	Sales and marketing		4,482			1,100		66
	General and administrative		3,581			1,450		83


	Total*	$	10,842		$	3,321	$	164






	*
	The table above includes the impact of the issuance of restricted stock at fair value.

Schedule of assumptions used to calculate stock-based compensation for each stock purchase right granted under the ESPP	'




		Year Ended
		December 31, 2013
	Expected term (years)		0.67
	Volatility		66.2	%
	Risk-free interest rate		0.07	%
	Dividend yield		—

NET_INCOME_LOSS_PER_SHARE_Tabl

NET INCOME (LOSS) PER SHARE (Tables)	12 Months Ended
NET INCOME (LOSS) PER SHARE (Tables)	Dec. 31, 2013
NET INCOME (LOSS) PER SHARE	'
Schedule of computation of net loss per common share	'

	The following table sets forth the computation of net loss per common share (in thousands, except per share amounts):


		Years Ended December 31,
		2013			2012			2011
	Net loss	$	(20,932	)	$	(10,343	)	$	(4,325	)
	Weighted-average shares used to compute basic and diluted net loss per share		15,177			8,024			7,600


	Basic and diluted net loss per share	$	(1.38	)	$	(1.29	)	$	(0.57	)




Schedule of anti-dilutive securities that were excluded from the calculation of diluted net loss per share attributable to common stockholders	'

	The following securities were excluded from the calculation of diluted net loss per share attributable to common stockholders because their effect would have been anti-dilutive for the periods presented (in thousands):


		Years Ended December 31,
		2013			2012			2011
	Convertible preferred stock		—			19,479			16,546
	Employee stock options		7,409			5,830			2,797
	Shares subject to repurchase		316			—			—
	Restricted stock units (RSUs)		383			—			—
	Employee stock purchase plan		58			—			—
	Convertible preferred stock warrants		—			267			267


			8,166			25,576			19,610

INCOME_TAXES_Tables

INCOME TAXES (Tables)	12 Months Ended
INCOME TAXES (Tables)	Dec. 31, 2013
INCOME TAXES	'
Schedule of domestic and foreign components of income (loss) before income taxes	'

	The following table presents domestic and foreign components of income (loss) before income taxes for the periods presented (in thousands):


		Years Ended December 31,
		2013			2012			2011
	Domestic	$	(21,568	)	$	(10,637	)	$	(4,401	)
	International		921			378			104


	Total	$	(20,647	)	$	(10,259	)	$	(4,297	)




Schedule of components of provision for income taxes	'

	The components of provision for income taxes were as follows (in thousands):


		Years Ended
		December 31,
		2013			2012			2011
	Current:
	Federal	$	—		$	—		$	—
	State		(4	)		11			2
	Foreign		289			73			26


	Total provision for income taxes	$	285		$	84		$	28




Schedule of reconciliation of the statutory federal rate and the Company's effective tax rate	'




		Years Ended December 31,
		2013			2012			2011
	Tax benefit at federal statutory rate		34	%		34	%		34	%
	State income taxes, net of federal effect		0.01			(0.07	)		(0.04	)
	Foreign rate differential		0.12			0.54			0.04
	Change in valuation allowance		(28.42	)		(25.16	)		(35.29	)
	Meals and entertainment		(2.07	)		(1.98	)		(2.49	)
	Warrant liability		(7.81	)		(7.65	)		(1.68	)
	Research Credits		2.79			0			4.72
	Other		0			(0.50	)		0.01


	Total provision		(1.38	)%		(0.82	)%		(0.73	)%




Schedule of components of the Company's deferred tax assets and liabilities	'

	The following table presents the significant components of the Company's deferred tax assets and liabilities for the periods presented (in thousands):


		December 31,
		2013			2012
	Deferred tax assets:
	Tax credit carry-forwards	$	2,256		$	843
	Net operating loss carry-forwards		13,118			8,377
	Charitable Contributions		133			—
	Accrued liabilities and allowances		5,421			2,292


	Gross deferred tax asset		20,928			11,512
	Valuation allowance		(15,762	)		(8,831	)


	Net deferred tax assets		5,166			2,681


	Deferred tax liability:
	Depreciation and amortization		(5,166	)		(2,681	)


	Gross deferred tax liability		(5,166	)		(2,681	)


	Net deferred tax assets (liabilities)	$	—		$	—




Schedule of reconciliation of the beginning and ending amount of unrecognized tax benefits (excluding interest and penalties)	'

	The table below provides a reconciliation of the beginning and ending amount of unrecognized tax benefits (excluding interest and penalties) for the years ended December 31, 2013, 2012 and 2011 (in thousands):


		December 31,
		2013			2012			2011
	Unrecognized benefit—beginning of period	$	272		$	184		$	83
	Gross increases—prior year tax positions		126			10			—
	Gross increases—current year tax positions		271			78			101


	Unrecognized benefit—end of period	$	669		$	272		$	184

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
COMMITMENTS AND CONTINGENCIES (Tables)	Dec. 31, 2013
COMMITMENTS AND CONTINGENCIES	'
Schedule of future minimum lease payments under non-cancelable operating leases	'

	Approximate remaining future minimum lease payments under these non-cancelable operating leases as of December 31, 2013 were as follows (in thousands):


	Year ending December 31,	Future Payments
	2014	$	4,934
	2015		11,506
	2016		12,730
	2017		12,204
	2018		10,881
	Thereafter		38,473


		$	90,728

SEGMENTS_Tables

SEGMENTS (Tables)	12 Months Ended
SEGMENTS (Tables)	Dec. 31, 2013
SEGMENTS	'
Schedule of total revenue generated through sales personnel located in the respective locations	'

	The following table summarizes total revenue generated through sales personnel located in the respective locations (in thousands):


		Years Ended December 31,
		2013		2012		2011
	North America	$	213,601	$	96,289	$	43,415
	All Other Countries		27,004		10,300		1,237


	Total revenue	$	240,605	$	106,589	$	44,652




Schedule of total long-lived assets in the respective locations	'

	The following table summarizes total long-lived assets in the respective locations (in thousands):


		December 31,
		2013		2012
	North America	$	23,956	$	9,959
	All Other Countries		1,838		980


	Total long-lived assets	$	25,794	$	10,939

NATURE_OF_BUSINESS_AND_SUMMARY3

NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)	1 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2013
	Sep. 30, 2013	item
NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	'	'
Number of cities in which the Company has offices	'	7
Initial public offering	'	'
Number of shares of common stock sold by selling stockholders	600,000	'
Aggregate net proceeds received from offering	'	$107,880,000
Initial Public Offering	'	'
Initial public offering	'	'
Number of shares of common stock sold by the entity	4,000,000	'
Issuance Price Per Share (in dollars per share)	29	'
Total gross proceeds from the offering	116,000,000	'
Aggregate net proceeds received from offering	103,300,000	'

NATURE_OF_BUSINESS_AND_SUMMARY4

NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 2) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Changes in the allowance for doubtful accounts	'	'	'
Balance, beginning of period	$468	$203	'
Add: bad debt expense	569	285	203
Less: write-offs, net of recoveries	20	-20	'
Balance, end of period	$1,057	$468	$203
Cash \| Credit concentration	'	'	'
Concentration of credit risk	'	'	'
Number of financial institutions where a significant portion of cash is held	1	'	'
Accounts receivable \| Credit concentration	'	'	'
Concentration of credit risk	'	'	'
Number of customers	'	1	'

NATURE_OF_BUSINESS_AND_SUMMARY5

NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 3) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	item	Dec. 31, 2012	Dec. 31, 2011
Internal Use Software Development Costs	'	'	'
Amortization expense	$3.40	$2.30	$1.50
Impairment of Long-lived Assets	'	'	'
Impairment of long-lived assets	0	0	0
Revenue Recognition	'	'	'
Number of criteria's required to be met for revenue recognition	4	'	'
Sales and Marketing	'	'	'
Advertising costs	3.6	0.1	0.1
Computer hardware and purchased software \| Minimum	'	'	'
Property and equipment	'	'	'
Estimated useful life	'2 years	'	'
Computer hardware and purchased software \| Maximum	'	'	'
Property and equipment	'	'	'
Estimated useful life	'3 years	'	'
Capitalized internal use software costs	'	'	'
Property and equipment	'	'	'
Estimated useful life	'3 years	'	'
Internal Use Software Development Costs	'	'	'
Internal-use software costs capitalized	6.3	4.7	2.6
Amortization expense	$3.40	$2.30	$1.50
Capitalized internal use software costs \| Minimum	'	'	'
Property and equipment	'	'	'
Estimated useful life	'2 years	'	'
Capitalized internal use software costs \| Maximum	'	'	'
Property and equipment	'	'	'
Estimated useful life	'3 years	'	'
Office equipment, furniture and fixtures	'	'	'
Property and equipment	'	'	'
Estimated useful life	'5 years	'	'

NATURE_OF_BUSINESS_AND_SUMMARY6

NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 4) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2013
In Millions, unless otherwise specified			Stock options granted to nonemployees	Stock options granted to nonemployees
			Minimum	Maximum
Stock-based compensation	'	'	'	'
Period during which related services are rendered	'	'	'1 year	'4 years
Deferred Offering Costs	'	'	'	'
Deferred offering costs included in other assets	$0.10	$0.10	'	'

FAIR_VALUE_MEASUREMENTS_Detail

FAIR VALUE MEASUREMENTS (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of the convertible preferred stock warrants measured and recorded at fair value on a recurring basis, using significant unobservable inputs (Level 3)	'	'	'
Balance at beginning of period	$2,741	$433	$138
Changes in fair value of warrants	4,740	2,308	295
Conversion of warrants to common stock	-7,481	'	'
Balance at end of period	'	2,741	433
Recurring \| Fair Value \| Convertible preferred stock warrant liability	'	'	'
Fair value measurements	'	'	'
Financial liabilities	'	-2,741	'
Recurring \| Fair Value \| Money market funds (included in cash and cash equivalents)	'	'	'
Fair value measurements	'	'	'
Financial assets	2,900	2,900	'
Recurring \| Level 1 \| Money market funds (included in cash and cash equivalents)	'	'	'
Fair value measurements	'	'	'
Financial assets	2,900	2,900	'
Recurring \| Level 3 \| Convertible preferred stock warrant liability	'	'	'
Fair value measurements	'	'	'
Financial liabilities	'	($2,741)	'

CASH_AND_CASH_EQUIVALENTS_Deta

CASH AND CASH EQUIVALENTS (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash and cash equivalents	'	'	'	'
Total cash and cash equivalents	$113,873	$14,896	$5,071	$8,523
Cash	'	'	'	'
Cash and cash equivalents	'	'	'	'
Total cash and cash equivalents	110,973	11,996	'	'
Money market funds	'	'	'	'
Cash and cash equivalents	'	'	'	'
Total cash and cash equivalents	$2,900	$2,900	'	'

PROPERTY_EQUIPMENT_AND_SOFTWAR2

PROPERTY, EQUIPMENT AND SOFTWARE, NET (Details) (USD $)	12 Months Ended
PROPERTY, EQUIPMENT AND SOFTWARE, NET (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property, equipment and software	'	'	'
Total	$37,279,000	$17,320,000	'
Accumulated depreciation and amortization	-11,485,000	-6,381,000	'
Total property, equipment and software, net	25,794,000	10,939,000	'
Depreciation and amortization expense, excluding amortization of internal use software costs	4,500,000	1,300,000	500,000
Amortization expense	3,400,000	2,300,000	1,500,000
Capital leases	600,000	0	'
Capitalized internal use software costs	'	'	'
Property, equipment and software	'	'	'
Total	14,030,000	10,441,000	'
Amortization expense	3,400,000	2,300,000	1,500,000
Computer hardware and software	'	'	'
Property, equipment and software	'	'	'
Total	17,077,000	4,281,000	'
Furniture and fixtures	'	'	'
Property, equipment and software	'	'	'
Total	1,735,000	816,000	'
Leasehold improvements	'	'	'
Property, equipment and software	'	'	'
Total	815,000	656,000	'
Construction in progress	'	'	'
Property, equipment and software	'	'	'
Total	$3,622,000	$1,126,000	'

ACCRUED_AND_OTHER_CURRENT_LIAB2

ACCRUED AND OTHER CURRENT LIABILITIES (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
ACCRUED AND OTHER CURRENT LIABILITIES	'	'
Payroll and related expenses	$10,722	$3,357
Accrued vacation	2,220	991
Professional services	650	268
Accrued credit cards	774	122
Early exercise of unvested stock options	1,107	451
Employee stock purchase plan	1,427	'
Other accrued expenses	4,684	997
Total accrued and other current liabilities	$21,584	$6,186

CAPITAL_LEASES_Details

CAPITAL LEASES (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
CAPITAL LEASES	'	'
Property and equipment acquired under capital lease agreements	$600,000	$0
Accumulated depreciation of property and equipment acquired under capital leases agreements	0	0
Approximate remaining future minimum lease payments under non-cancelable capital leases	'	'
2014	223,000	'
2015	223,000	'
2016	205,000	'
Total minimum lease payments	651,000	'
Less: amount representing interest and taxes	-36,000	'
Less: current portion of minimum lease payments	-203,000	'
Capital lease obligations, net of current portion	$412,000	'

OTHER_INCOME_EXPENSENET_Detail

OTHER INCOME (EXPENSE)-NET (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
OTHER INCOME (EXPENSE)-NET	'	'	'
Gain (loss) on foreign translation	($205)	$43	'
Other non-operating income (loss), net	-103	92	33
Total other income (expense)-net	($308)	$135	$33

DEBT_Details

DEBT (Details) (USD $)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Jun. 30, 2013

Dec. 31, 2013

Dec. 20, 2013

Dec. 31, 2013

Dec. 20, 2013

Dec. 31, 2013

Dec. 20, 2013

Dec. 31, 2013

Dec. 20, 2013

Dec. 31, 2013

Apr. 30, 2010

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Mar. 31, 2012

Feb. 28, 2013

Base rate

Federal funds rate

Daily adjusting LIBOR rate

Comerica Bank Prime Rate

Revolving line of credit, as amended in June 2013

Loan Facility

Revolving line of credit

Letter of credit subfacility

Swing line subfacility

Secured term loan facility

VLL Agreement

Term loans

Revolving line of credit amended in March 2012

Revolving line of credit amended in February 2013

Minimum

Maximum

Base rate

LIBOR

Minimum

Maximum

LIBOR

Minimum

Maximum

item

Base rate

LIBOR

Base rate

LIBOR

Base rate

LIBOR

Base rate

LIBOR

Debt

Maximum amount available for borrowing

$35,000,000

$80,000,000

$5,000,000

$1,500,000

$20,000,000

$3,000,000

$15,000,000

Additional revolving commitments

25,000,000

Maximum amount available for borrowing expressed as a percentage of certain eligible accounts

85.00%

Period of accounts aged over specified term excluded from eligible accounts

'120 days

Percentage of accounts aged over 120 days excluded from eligible accounts

25.00%

Period of 25% of accounts aged over specified term excluded from eligible accounts

'120 days

Variable rate basis

'base rate

'federal funds rate

'daily adjusting LIBOR rate

'Comerica Bank Prime Rate

'LIBOR

'base rate

'LIBOR

Applicable margin over variable rate basis (as a percent)

1.00%

2.75%

1.75%

2.75%

2.50%

3.50%

2.75%

3.75%

3.50%

4.50%

4.75%

Interest rate (as a percent)

2.99%

4.99%

Maximum borrowing capacity under the loan agreement

1,000,000

Number of remaining equal monthly installments

Fixed interest rate (as a percent)

13.00%

Principal amount outstanding under the loan

100,000

Period of interest only monthly installments

'3 months

'6 months

Quarterly principal installments

1,300,000

Liquidity ratio

1.1

Period from month end for submission of monthly consolidated financial statements in breach of the covenant

'30 days

Repayment period of growth capital advances

'24 months

Future principal payments of long-term debt

2015

5,000,000

2016

5,000,000

2017

5,000,000

2018

5,000,000

Total

20,000,000

Long-term debt, net of current portion

19,568,000

4,978,000

Amount outstanding

$1,900,000

$7,200,000

$5,000,000

STOCKHOLDERS_EQUITY_DEFICIT_De

STOCKHOLDERS' EQUITY (DEFICIT) (Details) (USD $)

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

0 Months Ended

Sep. 30, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Apr. 30, 2010

Sep. 30, 2013

Dec. 31, 2012

Sep. 25, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Sep. 30, 2013

Sep. 25, 2013

Employee Stock Purchase Plan

Options

Restricted stock units (RSUs)

Stock option and restricted stock unit grants

Loan and security agreement

Agreement for obtaining line of credit

Convertible Preferred Stock

Series A

Series B

Series C

Series C-1

Common stock, $0.001 par value

Undesignated preferred stock

Initial Public Offering

Series A convertible preferred stock warrant

Loan and security agreement

Agreement for obtaining line of credit

Series A

STOCKHOLDERS' EQUITY (DEFICIT)

Number of shares of common stock sold by the entity

1,116,030

2,932,675

4,000,000

Number of shares of common stock sold by selling stockholders

600,000

Issuance Price Per Share (in dollars per share)

$5.87

$11.76

$29

Total gross proceeds from the offering

$116,000,000

Aggregate net proceeds received from offering

107,880,000

103,300,000

Number of shares of common stock issued upon conversion of convertible securities

19,478,932

104,997

Shares Authorized

10,884,902

4,811,855

1,116,030

2,975,228

100,000,000

Shares issued

10,618,372

4,811,855

1,116,030

2,932,675

Shares outstanding

10,618,372

4,811,855

1,116,030

2,932,675

Liquidation Preference

9,860,000

12,500,000

8,187,000

34,500,000

Common stock, par value (in dollars per share)

$0.00

Shares authorized

1,000,000,000

35,850,100

1,000,000,000

35,850,100

Shares issued

32,825,992

8,680,041

32,825,992

8,680,041

Shares outstanding

32,825,992

8,680,041

32,825,992

8,680,041

Number of shares called by warrant

161,533

104,997

Exercise price of warrants (in dollars per share)

$0.93

Expiration period of warrants

'10 years

'7 years

Estimated fair value of warrants

22,000

10,000

4,500,000

2,900,000

Warrants outstanding

$2,741,000

Weighted-average assumptions

Expected dividend yield (as a percent)

0.00%

Expected volatility (as a percent)

70.50%

Risk-free interest rate (as a percent)

3.96%

3.33%

Expected term

'10 years

'7 years

Shares of capital stock reserved for issuance

Total shares reserved

13,404,259

1,000,000

7,410,588

382,402

4,611,269

STOCKHOLDERS_EQUITY_DEFICIT_De1

STOCKHOLDERS' EQUITY (DEFICIT) (Details 2) (USD $)

12 Months Ended

Dec. 31, 2013

Sep. 18, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

2013 Equity Incentive Plan

Options

Incentive stock options

Options and stock appreciation rights

Maximum

2008 Equity Incentive Plan

2013 Equity Incentive Plan

Maximum

Minimum

Maximum

Minimum

Maximum

Equity Incentive Plans

Exercise price as a percentage of the fair market value of the common stock

100.00%

Expiration period

'10 years

Vesting period

'4 years

Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant

14,738

33,080

Number of unvested shares

315,579

449,622

170,543

Number of shares of unvested stock repurchased

5,834

8,959

6,250

Common stock reserved for issuance

5,000,000

Number of shares added to current plan for award granted but not exercised in full, pursuant to the terminated equity incentive plan

7,900,000

Annual increase in number of shares available for issuance on first day of each fiscal year following latest fiscal year

4,000,000

Annual increase in number of shares available for issuance on first day of each fiscal year following latest fiscal year as a percentage of outstanding common stock, as on last day of the immediately preceding fiscal year

5.00%

Number of Shares Outstanding

Balance at the beginning of the period (in shares)

5,832,705

2,807,362

1,797,283

Options granted (weighted average fair value of $10.47 , $5.32 and $0.75 per share, respectively) (in shares)

2,251,848

3,962,055

1,799,350

Options exercised (in shares)

-406,323

-747,658

-339,354

Options forfeited (in shares)

-267,642

-189,054

-449,917

Balance at the end of the period (in shares)

7,410,588

5,832,705

2,807,362

1,797,283

Weighted average fair value (in dollars per share)

$10.47

$5.32

$0.75

Options vested and expected to vest (in shares)

6,789,538

5,148,950

Options vested and exercisable (in shares)

2,796,556

1,510,615

Weighted-Average Exercise Price

Balance at the beginning of the period (in dollars per share)

$3.65

$0.55

$0.20

Options granted (weighted average fair value of $10.47, $5.32 and $0.75 per share, respectively) (in dollars per share)

$14.51

$5.20

$0.92

Options exercised (in dollars per share)

$3.23

$1.02

$0.59

Options forfeited (in dollars per share)

$3.97

$1.64

$0.68

Balance at the end of the period (in dollars per share)

$6.97

$3.65

$0.55

$0.20

Options vested and expected to vest (in dollars per share)

$6.75

$3.58

Options vested and exercisable (in dollars per share)

$3.08

$1.97

Weighted-Average Remaining Contractual Life

Balance at the beginning of the period

'8 years 6 months

'9 years 1 month 6 days

'8 years 10 months 24 days

'9 years 2 months 12 days

Balance at the end of the period

'8 years 6 months

'9 years 1 month 6 days

'8 years 10 months 24 days

'9 years 2 months 12 days

Options vested and expected to vest

'8 years 4 months 24 days

'9 years

Options vested and exercisable

'7 years 9 months 18 days

'8 years 2 months 12 days

Aggregate Intrinsic Value

Balance at the beginning of the period

$44,073,000

$4,212,000

$135,000

Balance at the end of the period

404,106,000

44,073,000

4,212,000

135,000

Options vested and expected to vest

371,699,000

39,307,000

Options vested and exercisable

163,338,000

13,951,000

Total intrinsic value of options exercised

$11,900,000

$1,100,000

$100,000

STOCKHOLDERS_EQUITY_DEFICIT_De2

STOCKHOLDERS' EQUITY (DEFICIT) (Details 3) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Assumptions used to value stock-based awards granted to employees	'	'	'
Expected term	'8 months 1 day	'	'
Dividend yield (as a percent)	0.00%	'	'
Options	'	'	'
Options Outstanding	'	'	'
Number Outstanding (in shares)	7,410,588	'	'
Weighted-Average Life	'8 years 6 months	'	'
Options Vested and Exercisable	'	'	'
Number Vested and Exercisable (in shares)	2,796,556	'	'
Weighted-Average Life	'7 years 9 months 18 days	'	'
Expected dividends	$0	'	'
Assumptions used to value stock-based awards granted to employees	'	'	'
Volatility, lower end (as a percent)	53.80%	61.20%	56.10%
Volatility, higher end (as a percent)	64.90%	63.40%	66.70%
Risk-free interest rate, lower end (as a percent)	1.04%	0.70%	1.13%
Risk-free interest rate, higher end (as a percent)	1.88%	1.21%	3.06%
Dividend yield (as a percent)	0.00%	'	'
Options \| Minimum	'	'	'
Assumptions used to value stock-based awards granted to employees	'	'	'
Expected term	'5 years 3 months 18 days	'5 years 3 months 18 days	'5 years 4 months 24 days
Options \| Maximum	'	'	'
Assumptions used to value stock-based awards granted to employees	'	'	'
Expected term	'6 years 7 months 6 days	'7 years 3 months 18 days	'6 years 1 month 6 days
Options \| $0.13	'	'	'
Summary of options outstanding and vested	'	'	'
Exercise Prices (in dollars per share)	$0.13	'	'
Options Outstanding	'	'	'
Number Outstanding (in shares)	40,000	'	'
Weighted-Average Life	'5 years	'	'
Options Vested and Exercisable	'	'	'
Number Vested and Exercisable (in shares)	40,000	'	'
Weighted-Average Life	'5 years	'	'
Options \| $0.16	'	'	'
Summary of options outstanding and vested	'	'	'
Exercise Prices (in dollars per share)	$0.16	'	'
Options Outstanding	'	'	'
Number Outstanding (in shares)	538,816	'	'
Weighted-Average Life	'6 years	'	'
Options Vested and Exercisable	'	'	'
Number Vested and Exercisable (in shares)	512,612	'	'
Weighted-Average Life	'6 years	'	'
Options \| $0.27	'	'	'
Summary of options outstanding and vested	'	'	'
Exercise Prices (in dollars per share)	$0.27	'	'
Options Outstanding	'	'	'
Number Outstanding (in shares)	494,750	'	'
Weighted-Average Life	'6 years 10 months 24 days	'	'
Options Vested and Exercisable	'	'	'
Number Vested and Exercisable (in shares)	395,126	'	'
Weighted-Average Life	'6 years 10 months 24 days	'	'
Options \| $1.07	'	'	'
Summary of options outstanding and vested	'	'	'
Exercise Prices (in dollars per share)	$1.07	'	'
Options Outstanding	'	'	'
Number Outstanding (in shares)	1,130,951	'	'
Weighted-Average Life	'7 years 9 months 18 days	'	'
Options Vested and Exercisable	'	'	'
Number Vested and Exercisable (in shares)	632,230	'	'
Weighted-Average Life	'7 years 8 months 12 days	'	'
Options \| $2.97	'	'	'
Summary of options outstanding and vested	'	'	'
Exercise Prices (in dollars per share)	$2.97	'	'
Options Outstanding	'	'	'
Number Outstanding (in shares)	188,793	'	'
Weighted-Average Life	'8 years 6 months	'	'
Options Vested and Exercisable	'	'	'
Number Vested and Exercisable (in shares)	66,029	'	'
Weighted-Average Life	'8 years 6 months	'	'
Options \| $3.55	'	'	'
Summary of options outstanding and vested	'	'	'
Exercise Prices (in dollars per share)	$3.55	'	'
Options Outstanding	'	'	'
Number Outstanding (in shares)	186,000	'	'
Weighted-Average Life	'8 years 7 months 6 days	'	'
Options Vested and Exercisable	'	'	'
Number Vested and Exercisable (in shares)	64,524	'	'
Weighted-Average Life	'8 years 7 months 6 days	'	'
Options \| $6.58	'	'	'
Summary of options outstanding and vested	'	'	'
Exercise Prices (in dollars per share)	$6.58	'	'
Options Outstanding	'	'	'
Number Outstanding (in shares)	2,682,945	'	'
Weighted-Average Life	'8 years 10 months 24 days	'	'
Options Vested and Exercisable	'	'	'
Number Vested and Exercisable (in shares)	1,049,812	'	'
Weighted-Average Life	'8 years 10 months 24 days	'	'
Options \| $11.21	'	'	'
Summary of options outstanding and vested	'	'	'
Exercise Prices (in dollars per share)	$11.21	'	'
Options Outstanding	'	'	'
Number Outstanding (in shares)	1,168,083	'	'
Weighted-Average Life	'9 years 2 months 12 days	'	'
Options Vested and Exercisable	'	'	'
Number Vested and Exercisable (in shares)	34,723	'	'
Weighted-Average Life	'9 years 2 months 12 days	'	'
Options \| $15.33	'	'	'
Summary of options outstanding and vested	'	'	'
Exercise Prices (in dollars per share)	$15.33	'	'
Options Outstanding	'	'	'
Number Outstanding (in shares)	753,050	'	'
Weighted-Average Life	'9 years 4 months 24 days	'	'
Options \| $20.05	'	'	'
Summary of options outstanding and vested	'	'	'
Exercise Prices (in dollars per share)	$20.05	'	'
Options Outstanding	'	'	'
Number Outstanding (in shares)	151,700	'	'
Weighted-Average Life	'9 years 7 months 6 days	'	'
Options Vested and Exercisable	'	'	'
Number Vested and Exercisable (in shares)	1,500	'	'
Weighted-Average Life	'9 years 7 months 6 days	'	'
Options \| $29.00	'	'	'
Summary of options outstanding and vested	'	'	'
Exercise Prices (in dollars per share)	$29	'	'
Options Outstanding	'	'	'
Number Outstanding (in shares)	22,500	'	'
Weighted-Average Life	'9 years 8 months 12 days	'	'
Options \| $48.78	'	'	'
Summary of options outstanding and vested	'	'	'
Exercise Prices (in dollars per share)	$48.78	'	'
Options Outstanding	'	'	'
Number Outstanding (in shares)	26,000	'	'
Weighted-Average Life	'9 years 10 months 24 days	'	'
Options \| $63.37	'	'	'
Summary of options outstanding and vested	'	'	'
Exercise Prices (in dollars per share)	$63.37	'	'
Options Outstanding	'	'	'
Number Outstanding (in shares)	27,000	'	'
Weighted-Average Life	'9 years 9 months 18 days	'	'

STOCKHOLDERS_EQUITY_DEFICIT_De3

STOCKHOLDERS' EQUITY (DEFICIT) (Details 4) (USD $)	12 Months Ended
STOCKHOLDERS' EQUITY (DEFICIT) (Details 4) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allocation of stock-based compensation and restricted stock for employees and non-employees	'	'	'
Total	$10,842,000	$3,321,000	$164,000
Options	'	'	'
Allocation of stock-based compensation and restricted stock for employees and non-employees	'	'	'
Unamortized stock-based compensation expense related to unvested common stock options	21,700,000	12,500,000	700,000
Weighted-average period over which stock-based compensation expense will be recognized	'2 years 10 months 24 days	'	'
Cost of revenue	'	'	'
Allocation of stock-based compensation and restricted stock for employees and non-employees	'	'	'
Total	471,000	37,000	7,000
Research and development	'	'	'
Allocation of stock-based compensation and restricted stock for employees and non-employees	'	'	'
Total	2,308,000	734,000	8,000
Sales and marketing	'	'	'
Allocation of stock-based compensation and restricted stock for employees and non-employees	'	'	'
Total	4,482,000	1,100,000	66,000
General and administrative	'	'	'
Allocation of stock-based compensation and restricted stock for employees and non-employees	'	'	'
Total	$3,581,000	$1,450,000	$83,000

STOCKHOLDERS_EQUITY_DEFICIT_De4

STOCKHOLDERS' EQUITY (DEFICIT) (Details 5) (USD $)

12 Months Ended

1 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Aug. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Employee Stock Purchase Plan

Options to Nonemployees

Restricted Stock

Restricted Stock Units (RSUs)

2008 Equity Incentive Plan

Additional disclosure

Options granted (in shares)

8,500

Stock-based compensation expense

$10,842,000

$3,321,000

$164,000

$100,000

$1,000,000

Options outstanding (in shares)

8,900

12,400

Number of awards issued (in shares)

13,571

68,815

383,402

Number of awards cancelled (in shares)

1,000

Unrecognized compensation expense

14,500,000

Percentage of deduction from eligible compensation authorized by employee to purchase common stock at discount

15.00%

Offering ending period

'6 months

Purchase price expressed as a percentage of fair market value of common stock on the first or the last trading day of the offering period

85.00%

Total compensation costs related to rights to purchase common shares but not yet vested which will be recognized over the offering period

$1,800,000

Assumptions used to calculate stock-based compensation for each stock purchase right granted under the Employee Stock Purchase Plan (ESPP)

Expected term

'8 months 1 day

Volatility (as a percent)

66.20%

Risk-free interest rate (as a percent)

0.07%

Dividend yield (as a percent)

0.00%

NET_INCOME_LOSS_PER_SHARE_Deta

NET INCOME (LOSS) PER SHARE (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Computation of net loss per common share	'	'	'
Net loss (in dollars)	($20,932)	($10,343)	($4,325)
Weighted-average shares used to compute basic and diluted net loss per share	15,177	8,024	7,600
Basic and diluted net loss per share (in dollars per share)	($1.38)	($1.29)	($0.57)
Anti-dilutive securities that were excluded from the calculation of diluted net loss per share attributable to common stockholders	'	'	'
Anti-dilutive securities that were excluded from the calculation of diluted net loss per share attributable to common stockholders (in shares)	8,166	25,576	19,610
Convertible preferred stock	'	'	'
Anti-dilutive securities that were excluded from the calculation of diluted net loss per share attributable to common stockholders	'	'	'
Anti-dilutive securities that were excluded from the calculation of diluted net loss per share attributable to common stockholders (in shares)	'	19,479	16,546
Employee stock options	'	'	'
Anti-dilutive securities that were excluded from the calculation of diluted net loss per share attributable to common stockholders	'	'	'
Anti-dilutive securities that were excluded from the calculation of diluted net loss per share attributable to common stockholders (in shares)	7,409	5,830	2,797
Shares subject to repurchase	'	'	'
Anti-dilutive securities that were excluded from the calculation of diluted net loss per share attributable to common stockholders	'	'	'
Anti-dilutive securities that were excluded from the calculation of diluted net loss per share attributable to common stockholders (in shares)	316	'	'
Restricted stock units (RSUs)	'	'	'
Anti-dilutive securities that were excluded from the calculation of diluted net loss per share attributable to common stockholders	'	'	'
Anti-dilutive securities that were excluded from the calculation of diluted net loss per share attributable to common stockholders (in shares)	383	'	'
Employee Stock Purchase Plan	'	'	'
Anti-dilutive securities that were excluded from the calculation of diluted net loss per share attributable to common stockholders	'	'	'
Anti-dilutive securities that were excluded from the calculation of diluted net loss per share attributable to common stockholders (in shares)	58	'	'
Convertible preferred stock warrants	'	'	'
Anti-dilutive securities that were excluded from the calculation of diluted net loss per share attributable to common stockholders	'	'	'
Anti-dilutive securities that were excluded from the calculation of diluted net loss per share attributable to common stockholders (in shares)	'	267	267

INCOME_TAXES_Details

INCOME TAXES (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Components of domestic and foreign income (loss) before income taxes	'	'	'
Domestic	($21,568)	($10,637)	($4,401)
International	921	378	104
Loss before income taxes	-20,647	-10,259	-4,297
Current:	'	'	'
State	-4	11	2
Foreign	289	73	26
Total provision for income taxes	$285	$84	$28

INCOME_TAXES_Details_2

INCOME TAXES (Details 2)	12 Months Ended
INCOME TAXES (Details 2)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation between statutory federal rate and effective tax rate	'	'	'
Tax benefit at federal statutory rate (as a percent)	34.00%	34.00%	34.00%
State income taxes, net of federal effect (as a percent)	0.01%	-0.07%	-0.04%
Foreign rate differential (as a percent)	0.12%	0.54%	0.04%
Change in valuation allowance (as a percent)	-28.42%	-25.16%	-35.29%
Meals and entertainment (as a percent)	-2.07%	-1.98%	-2.49%
Warrant liability (as a percent)	-7.81%	-7.65%	-1.68%
Research Credits (as a percent)	2.79%	0.00%	4.72%
Other (as a percent)	0.00%	-0.50%	0.01%
Total provision (as a percent)	-1.38%	-0.82%	-0.73%

INCOME_TAXES_Details_3

INCOME TAXES (Details 3) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:	'	'
Tax credit carry-forwards	$2,256	$843
Net operating loss carry-forwards	13,118	8,377
Charitable Contributions	133	'
Accrued liabilities and allowances	5,421	2,292
Gross deferred tax asset	20,928	11,512
Valuation allowance	-15,762	-8,831
Net deferred tax assets	5,166	2,681
Deferred tax liability:	'	'
Depreciation and amortization	-5,166	-2,681
Gross deferred tax liability	($5,166)	($2,681)

INCOME_TAXES_Details_4

INCOME TAXES (Details 4) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2013
Federal	'
Net operating loss carry-forwards	'
Net operating loss carry-forwards	$43.90
State	'
Net operating loss carry-forwards	'
Net operating loss carry-forwards	$18.40

INCOME_TAXES_Details_5

INCOME TAXES (Details 5) (Research and development, USD $)	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2013
Federal	'
Tax credit carry-forwards	'
Tax credit carry-forwards	$1.70
State	'
Tax credit carry-forwards	'
Tax credit carry-forwards	$1.70

INCOME_TAXES_Details_6

INCOME TAXES (Details 6) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Federal	'
Operating Loss Carryforwards [Line Items]	'
Excess deduction that would not be recognized until stock option exercise deduction reduces taxes payable	($8.30)
California	'
Operating Loss Carryforwards [Line Items]	'
Excess deduction that would not be recognized until stock option exercise deduction reduces taxes payable	($1)

INCOME_TAXES_Details_7

INCOME TAXES (Details 7) (USD $)	12 Months Ended
INCOME TAXES (Details 7) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of the beginning and ending amount of unrecognized tax benefits (excluding interest and penalties)	'	'	'
Unrecognized benefit-beginning of period	$272,000	$184,000	$83,000
Gross increases-prior year tax positions	126,000	10,000	'
Gross increases-current year tax positions	271,000	78,000	101,000
Unrecognized benefit-end of period	669,000	272,000	184,000
Unrecognized tax benefits that would have no impact on effective tax rate if recognized	700,000	'	'
Cumulative interest and penalties related to the uncertain tax position	$0	'	'

COMMITMENTS_AND_CONTINGENCIES_1

COMMITMENTS AND CONTINGENCIES (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	item	Dec. 31, 2012	Dec. 31, 2011
Operating Leases	'	'	'
Rent expense	$4,300,000	$1,600,000	$700,000
Future minimum lease payments under non-cancelable operating leases	'	'	'
2014	4,934,000	'	'
2015	11,506,000	'	'
2016	12,730,000	'	'
2017	12,204,000	'	'
2018	10,881,000	'	'
Thereafter	38,473,000	'	'
Total future payments	90,728,000	'	'
Letter of Credit	'	'	'
Irrevocable letters of credit outstanding	3,400,000	200,000	100,000
Indemnification Agreements	'	'	'
Demands to provide indemnification	$0	'	'
Number of claims under indemnification agreements	0	'	'

SEGMENTS_Details

SEGMENTS (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	item	Dec. 31, 2012	Dec. 31, 2011
SEGMENTS	'	'	'
Number of business activities	1	'	'
Number of segment managers held accountable for operations, operating results or plans for levels or components below the consolidated unit level	0	'	'
Segments	'	'	'
Total revenue	$240,605	$106,589	$44,652
Total long-lived assets, net	25,794	10,939	'
North America	'	'	'
Segments	'	'	'
Total revenue	213,601	96,289	43,415
Total long-lived assets, net	23,956	9,959	'
All Other Countries	'	'	'
Segments	'	'	'
Total revenue	27,004	10,300	1,237
Total long-lived assets, net	$1,838	$980	'

SEGMENTS_Details_2

SEGMENTS (Details 2) (Accounts receivable, Credit concentration)	12 Months Ended
	Dec. 31, 2012
	item
Accounts receivable \| Credit concentration	'
Concentration of credit risk	'
Number of customers	1

SUBSEQUENT_EVENTS_Details

SUBSEQUENT EVENTS (Details) (USD $)	1 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2013	Feb. 28, 2014
		Subsequent event
		Follow-on public offering
Subsequent events	'	'
Number of shares of common stock sold by the entity	'	2,000,000
Number of shares of common stock sold by selling stockholders	600,000	3,000,000
Public offering price of the shares sold in the offering (in dollars per share)	'	$61
Gross proceeds from the offering to the Company	'	$122
Aggregate net proceeds received by the Company after deducting underwriters' discounts and commissions	'	$116.50