Rocket Fuel 10-Q 13 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 31, 2013
Document and Entity Information	'	'
Entity Registrant Name	'Rocket Fuel Inc.	'
Entity Central Index Key	'0001477200	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Amendment Flag	'false	'
Current Fiscal Year End Date	'--12-31	'
Entity Current Reporting Status	'No	'
Entity Filer Category	'Non-accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	32,821,242
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheet (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current Assets:	'	'
Cash and cash equivalents	$125,282	$14,896
Accounts receivable, net	67,984	47,333
Deferred tax assets	334	334
Prepaid expenses and other current assets	2,159	1,215
Total current assets	195,759	63,778
Property, equipment and software, net	20,941	10,939
Other assets	1,165	472
Total assets	217,865	75,189
Current Liabilities:	'	'
Accounts payable	34,088	17,482
Accrued and other current liabilities	15,707	6,186
Deferred revenue	451	187
Current portion of line of credit	11,853	'
Current portion of long-term debt	4,375	1,988
Total current liabilities	66,474	25,843
Line of credit - Less current portion	'	1,853
Long-term debt - Less current portion	10,625	3,125
Deferred rent - Less current portion	482	430
Deferred tax liabilities	334	334
Convertible preferred stock warrant liability	'	2,741
Total liabilities	77,915	34,326
Commitments and contingencies (Note11)	'	'
Stockholders' Equity (Note 8)	'	'
Common stock, $0.001 par value - 1,000,000,000 and 35,850,100 authorized as of September 30, 2013 and December 31, 2012, respectively; 32,807,784 and 8,680,041 issued and outstanding as of September 30, 2013 and December 31, 2012, respectively	33	8
Additional paid-in capital	182,332	3,865
Accumulated other comprehensive loss	-101	-84
Accumulated deficit	-42,314	-23,543
Total stockholders' equity	139,950	40,863
Total liabilities and stockholders' equity	217,865	75,189
Series A	'	'
Stockholders' Equity (Note 8)	'	'
Convertible preferred stock	'	9,788
Series B	'	'
Stockholders' Equity (Note 8)	'	'
Convertible preferred stock	'	9,935
Series C	'	'
Stockholders' Equity (Note 8)	'	'
Convertible preferred stock	'	6,501
Series C-1	'	'
Stockholders' Equity (Note 8)	'	'
Convertible preferred stock	'	$34,393

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheet (Parenthetical) (USD $)	Dec. 31, 2012
Common stock, par value (in dollars per share)	$0.00
Common stock, shares authorized	35,850,100
Common stock, shares issued	8,680,041
Common stock, shares outstanding	8,680,041
Series A	'
Convertible preferred stock, par value (in dollars per share)	$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
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
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
Convertible preferred stock, shares authorized	2,975,228
Convertible preferred stock, shares issued	2,932,675
Convertible preferred stock, shares outstanding	2,932,675

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Condensed Consolidated Statements of Operations	'	'	'	'
Revenue	$62,458	$26,902	$155,039	$66,494
Cost of revenue	31,877	14,955	81,529	36,988
Gross Profit	30,581	11,947	73,510	29,506
Operating expenses:	'	'	'	'
Research and development	4,464	1,066	10,587	2,604
Sales and marketing	21,644	10,351	56,293	25,893
General and administrative	8,719	1,675	19,671	4,245
Total operating expenses	34,827	13,092	86,551	32,742
Loss from operations	-4,246	-1,145	-13,041	-3,236
Other expense, net:	'	'	'	'
Interest expense	-251	-63	-604	-233
Other income (expense) - net	155	65	-213	157
Change in fair value of convertible preferred stock warrant liability	-2,385	-831	-4,740	-1,093
Other expense, net	-2,481	-829	-5,557	-1,169
Loss before income taxes	-6,727	-1,974	-18,598	-4,405
Provision for income taxes	-133	-28	-173	-67
Net loss	($6,860)	($2,002)	($18,771)	($4,472)
Basic and diluted net loss per share attributable to common stockholders (in dollars per share)	($0.61)	($0.25)	($2.01)	($0.56)
Basic and diluted weighted-average shares used to compute net loss per share attributable to common stockholders (in shares)	11,315	8,067	9,346	7,971

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Loss (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Consolidated Statements Of Comprehensive Loss	'	'	'	'
Net loss	($6,860)	($2,002)	($18,771)	($4,472)
Other comprehensive loss:	'	'	'	'
Foreign currency translation adjustments	24	-38	-17	-36
Comprehensive loss	($6,836)	($2,040)	($18,788)	($4,508)

Statement_of_Changes_in_Stockh

Statement of Changes in Stockholders' Equity (USD $)	Total	Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
In Thousands, except Share data, unless otherwise specified
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 common stock upon exercises of employee stock options, net of repurchases	438	'	1	437	'	'
Issuance of common stock upon exercises of employee stock options, net of repurchases (in shares)	'	'	382,281	'	'	'
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	'	'	'
Issuance of common stock from initial public offering, net of issuance costs	103,144	'	4	103,140	'	'
Issuance of common stock from initial public offering, net of issuance costs (in shares)	'	'	4,000,000	'	'	'
Stock-based compensation	6,713	'	'	6,713	'	'
Foreign currency translation adjustments	-17	'	'	'	-17	'
Net loss	-18,771	'	'	'	'	-18,771
Balance at Sep. 30, 2013	$139,950	'	$33	$182,332	($101)	($42,314)
Balance (in shares) at Sep. 30, 2013	'	'	32,807,784	'	'	'

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
OPERATING ACTIVITIES:	'	'
Net loss	($18,771)	($4,472)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'
Depreciation and amortization	4,583	2,461
Provision for doubtful accounts	521	63
Stock-based compensation	6,277	507
Issuance of restricted stock for services provided	'	20
Amortization of debt discount	1	6
Loss on disposal of property, equipment and software	-26	'
Change in fair value of preferred stock warrant liability	4,740	1,093
Changes in operating assets and liabilities:	'	'
Accounts receivable	-21,236	-15,586
Prepaid expenses and other current assets	-941	-679
Other assets	-700	-251
Accounts payable	12,532	3,951
Accrued and other liabilities	5,496	2,235
Deferred rent	100	315
Deferred revenue	264	18
Net cash used in operating activities	-7,160	-10,319
INVESTING ACTIVITIES:	'	'
Purchases of property, equipment and software	-5,564	-2,513
Capitalized internal use software development costs	-4,486	-3,294
Net cash used in investing activities	-10,050	-5,807
FINANCING ACTIVITIES:	'	'
Proceeds from issuance of common stock in initial public offering, net of underwriting discounts and commission	107,880	'
Payments of costs related to initial public offering	-1,534	'
Proceeds from the issuance of convertible preferred stock	'	34,500
Proceeds from the exercise of common stock warrants	97	'
Issuance costs related to convertible preferred stock	'	-105
Proceeds from exercise of vested common stock options	208	46
Proceeds from early exercise of unvested common stock options	1,058	378
Repurchases of common stock options early exercised	-11	-3
Borrowings from line of credit	10,000	4,000
Repayment of line of credit	'	-6,000
Proceeds from issuance of long-term debt	10,000	3,000
Repayment of long-term debt	-114	-311
Net cash provided by financing activities	127,584	35,505
EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	12	-51
CHANGE IN CASH AND CASH EQUIVALENTS	110,386	19,328
CASH AND CASH EQUIVALENTS-Beginning of period	14,896	5,071
CASH AND CASH EQUIVALENTS-End of period	125,282	24,399
SUPPLEMENTAL DISCLOSURES OF OTHER CASH FLOW INFORMATION:	'	'
Cash paid for income taxes	348	'
Cash paid for interest	543	233
SUPPLEMENTAL DISCLOSURES OF NONCASH INVESTING AND FINANCING ACTIVITIES:	'	'
Purchases of property and equipment recorded in accounts payable and accruals	4,952	232
Deferred offering costs recorded in accrued liabilities	3,194	'
Vesting of early exercised options	229	91
Stock-based compensation capitalized in internally developed software costs	437	0
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	9 Months Ended
	Sep. 30, 2013
NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	'
NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	'
	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 throughout the United States. The Company established a wholly-owned subsidiary in the United Kingdom in 2011, with branches in various countries through Europe, and a wholly-owned subsidiary in Germany 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, the aggregate net proceeds received by the Company totaled approximately $107.9 million.
	Basis of Presentation—The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes presented in the Company’s prospectus filed with the SEC on September 20, 2013 pursuant to Rule 424(b) under the Securities Act of 1933.
	The condensed consolidated balance sheet as of December 31, 2012 included herein was derived from the audited financial statements as of that date, but does not include all notes and other disclosures required by GAAP.
	In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, and cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for the full year 2013 or any future period.
	Principles of Consolidation—The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, which are engaged in marketing and selling advertising campaigns. All intercompany transactions and balances have been eliminated in consolidation.
	Use of Estimates—The preparation of unaudited condensed 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 unaudited condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Such estimates include, but are not limited to, provisions for doubtful accounts, the amount of software development costs which should be capitalized, future taxable income, the useful lives of long-lived assets and the assumptions used for purposes of determining stock-based compensation. Actual results could differ from those estimates.
	Foreign Currency Translation—Each of the Company’s foreign subsidiaries records its assets, liabilities and results of operations in its local currency, which is its functional currency. The Company translates these subsidiary consolidated financial statements into U.S. dollars each reporting period for purposes of consolidation.
	Assets and liabilities of the Company’s foreign subsidiaries 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, 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, 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 term debt and line of credit approximates its recorded amount at September 30, 2013 as the interest rate on the 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 three months 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 September 30, 2013, no customer accounted for 10% or more of accounts receivable.  As of December 31, 2012, one customer accounted for 10% of accounts receivable.
	During the three and nine months ended September 30, 2013 and 2012, 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):
		Nine Months
		Ended		Year Ended
		September 30,		December 31,
		2013		2012
	Allowance for doubtful accounts:
	Balance, beginning of period	$	468	$	203
	Bad debt expense	521		285
	Recoveries (write-offs), net	19		(20		)
	Balance, end of the period	$	1,008	$	468
	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 and amortization are removed from the balance sheet and any resulting gain or loss is reflected in operations in the period realized.
	Property and equipment are initially recorded at cost and depreciated using the straight-line method over the estimated useful lives of the assets. Depreciation and amortization periods for the Company’s property and equipment are as follows:
	Asset	Estimated
	Classification	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
	Leasehold improvements	Shorter of the lease term or estimated useful life
	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 $4.9 million and $3.3 million in internal-use software costs during the nine months ended September 30, 2013 and 2012, 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 two to three years. Amortization expense totaled $0.9 million and $0.6 million for the three months ended September 30, 2013 and 2012, respectively, and $2.5 million and $1.6 million for the nine months ended September 30, 2013 and 2012, 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 its estimated useful life is no longer appropriate. If indicators of impairment exist and the undiscounted projected cash flows associated with such asset is less than the carrying amount of the asset, an impairment loss is recorded to write the asset down to its estimated fair value. Fair value is estimated based on discounted future cash flows. No impairment charges were recorded during the three and nine months ended September 30, 2013 and 2012.
	Revenue Recognition—We generate 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; and
	·                  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 to be delivered, the agreed upon rate 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 acts as the principal in 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 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 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 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 regularly reviews 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, and is typically recognized within twelve months.
	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, such as facility-related expenses, insurance, supplies and other fixed costs, associated with the Company’s engineering and research and development departments, as well as costs for contracted services and supplies. The Company reviews costs incurred in the application development stage and assesses such costs for 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, such as facility-related expenses, insurance, supplies and other fixed costs, certain advertising costs, travel, trade shows and marketing materials. The Company incurred advertising costs of $1.6 million and $0.1 million for the three months ended September 30, 2013 and 2012, respectively, and $3.3 million and $0.1 million for the nine months ended September 30, 2013 and 2012, 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.
	Stock-Based Compensation—The Company measures compensation expense for all stock-based payment awards, including stock options and restricted stock units granted to employees, based on the estimated fair values on the date of the grant. The fair value of each stock-based payment award granted is estimated using the Black-Scholes option pricing model. Stock-based compensation is recognized on a straight-line basis over the requisite service 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 nonemployees based on the fair value of the awards determined using the Black-Scholes option pricing model. The fair value of stock options granted to nonemployees 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 sheet as of December 31, 2012. The fully vested convertible preferred stock warrants are 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 September 30, 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 carryforwards 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 carryforwards, research and development and other tax credits, the Company has provided a full valuation allowance reserved against such assets as of September 30, 2013 and December 31, 2012.
	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.
	Deferred Offering Costs—Deferred offering costs consisted primarily of direct incremental costs related to the Company’s IPO 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, 2012.  Upon the completion of the IPO, these amounts were offset against the proceeds of the IPO.
Comprehensive 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 three and nine months ended September 30, 2013 and 2012.
Recently Issued Accounting Pronouncements
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 in the notes to the financial statements will still be required. 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 condensed financial statements.

FAIR_VALUE_MEASUREMENTS

FAIR VALUE MEASUREMENTS	9 Months Ended
	Sep. 30, 2013
FAIR VALUE MEASUREMENTS	'
FAIR VALUE MEASUREMENTS	'
	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. The valuations are based on quoted prices of the underlying security that are readily and regularly available in an active market, and accordingly, a significant degree of judgment is not required. As of September 30, 2013 and December 31, 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 September 30, 2013 and December 31, 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 September 30, 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 or debt with similar terms, the carrying value of the line of credit and term-debt approximate fair value (using Level 2 inputs).
	Level 3 includes convertible preferred stock warrant liability, the value of which is determined based on an option-pricing model that takes into account the expected term as well as multiple inputs, such as the Company’s stock price, risk-free interest rates and expected volatility.
	The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis as of September 30, 2013 and December 31, 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):
	September 30, 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 are classified as liabilities in the consolidated balance sheet as of December 31, 2012. The warrants are subject to remeasurement at each balance sheet date, and any change in fair value is 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):
		Three Months Ended					Nine Months Ended
		September 30,					September 30,
		2013			2012		2013			2012
	Balance at beginning of period	$	5,096		$	695	$	2,741		$	433
	Changes in fair value of warrants	2,385			831		4,740			1,093
	Conversion of warrants to common stock	(7,481		)	—		(7,481		)	—
	Balance at end of period	$	—		$	1,526	$	—		$	1,526

CASH_AND_CASH_EQUIVALENTS

CASH AND CASH EQUIVALENTS	9 Months Ended
	Sep. 30, 2013
CASH AND CASH EQUIVALENTS	'
CASH AND CASH EQUIVALENTS	'
	3.                                     CASH AND CASH EQUIVALENTS
	Cash and cash equivalents as of September 30, 2013 and December 31, 2012 consisted of the following (in thousands):
		September 30,		December 31,
		2013		2012
	Cash and cash equivalents
	Cash	$	122,382	$	11,996
	Money market funds	2,900		2,900
	Total cash and cash equivalents	$	125,282	$	14,896

PROPERTY_EQUIPMENT_AND_SOFTWAR

PROPERTY, EQUIPMENT AND SOFTWARE	9 Months Ended
	Sep. 30, 2013
PROPERTY, EQUIPMENT AND SOFTWARE	'
PROPERTY, EQUIPMENT AND SOFTWARE	'
	4.                                      PROPERTY, EQUIPMENT AND SOFTWARE
	Property, equipment and software as of September 30, 2013 and December 31, 2012 consisted of the following (in thousands):
		September 30,			December 31,
		2013			2012
	Capitalized internal use software costs	$	15,364		$	10,441
	Computer hardware and software	12,970			4,281
	Furniture and fixtures	1,624			816
	Leasehold improvements	807			656
	Construction in progress	1,115			1,126
	Total	31,880			17,320
	Accumulated depreciation and amortization	(10,939		)	(6,381		)
	Net property, equipment and software	$	20,941		$	10,939
	Total depreciation and amortization expense, excluding amortization of internal use software costs, was $0.8 million and $0.4 million for the three months ended September 30, 2013 and 2012, respectively, and $2.1 million and $0.9 million for the nine months ended September 30, 2013 and 2012, respectively. Amortization expense of internal use software costs was $0.9 million and $0.6 million for the three months ended September 30, 2013 and 2012, respectively, and $2.5 million and $1.6 million for the nine months ended September 30, 2013 and 2012, respectively. The Company held no capital leases as of September 30, 2013 and December 31, 2012.

ACCRUED_AND_OTHER_CURRENT_LIAB

ACCRUED AND OTHER CURRENT LIABILITIES	9 Months Ended
	Sep. 30, 2013
ACCRUED AND OTHER CURRENT LIABILITIES	'
ACCRUED AND OTHER CURRENT LIABILITIES	'
	5.                                      ACCRUED AND OTHER CURRENT LIABILITIES
	Accrued and other current liabilities as of September 30, 2013 and December 31, 2012 consisted of the following (in thousands):
		September 30,		December 31,
		2013		2012
	Payroll and related expenses	$	7,765	$	3,357
	Accrued vacation	1,791		991
	Professional services	1,932		268
	Accrued credit cards	751		122
	Early exercise of unvested stock options	1,269		451
	Other accrued expenses	2,199		997
	Total	$	15,707	$	6,186

OTHER_INCOME_EXPENSE_NET

OTHER INCOME (EXPENSE), NET	9 Months Ended
	Sep. 30, 2013
OTHER INCOME (EXPENSE), NET	'
OTHER INCOME (EXPENSE), NET	'
	6.                                      OTHER INCOME (EXPENSE), NET
	Other income (expense), net for the three and nine months ended September 30, 2013 and 2012 consisted of the following (in thousands):
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013			2012
	Gain (loss) on foreign translation	$	108	$	31	$	(352	)	$	31
	Other non-operating income (loss), net	47		34		139			126
	Total	$	155	$	65	$	(213	)	$	157

DEBT

DEBT	9 Months Ended
	Sep. 30, 2013
DEBT	'
DEBT	'
	7.                                      DEBT
	Line of Credit—In April 2010, the Company entered into a loan and security agreement (the “Comerica Agreement”), with Comerica Bank (“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, is not to exceed the lesser of $35.0 million or an amount equal to 85% of certain eligible accounts receivable. Eligible accounts exclude, among others, accounts that have aged over 120 days, and accounts in which 25% of the total account is aged over 120 days, and certain other accounts such as governmental, intercompany, employee and certain foreign accounts. The revolving line of credit has a maturity date of July 26, 2014 and may be repaid and redrawn at any time prior to the maturity date, at which time all advances and any accrued and unpaid interest are due and payable. Interest is charged at LIBOR, plus a 2.75% applicable margin, which equaled 2.93% and 2.99% as of September 30, 2013 and December 31, 2012, respectively. As of September 30, 2013 and December 31, 2012, the Company had $11.9 million and $1.9 million outstanding under the revolving line of credit, respectively.
	The Company’s obligations under the Comerica Agreement are secured by substantially all of the Company’s assets.
	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 may be drawn on before February 13, 2014 and are 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 will be due and payable. Interest on outstanding balances is charged at LIBOR, plus a 4.75% applicable margin, which equaled 4.93% and 4.99% as of September 30, 2013 and December 31, 2012, respectively. As of September 30, 2013 and December 31, 2012, the principal amount of $15.0 million and $5.0 million, respectively, was outstanding under the loan.
	Venture Debt—In April 2010, the Company entered into a loan and security agreement (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 contains 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 September 30, 2013.
	Covenants
	The Comerica Agreement includes, and the VLL Agreement included, customary affirmative and negative covenants, including, among others, covenants limiting the ability of the Company and its subsidiaries to dispose of assets, merge or consolidate, incur indebtedness, grant liens, make certain restricted payments, make investments, make acquisitions and enter into transactions with affiliates, in each case subject to customary exceptions.  In addition, the Comerica Agreement provides that the Company must maintain compliance with a minimum EBITDA covenant and a minimum liquidity, each as determined in accordance with the Comerica Agreement and described in more detail below.
	Under the terms of the Comerica Agreement, the Company is required to comply with the following financial covenants:
	1. EBITDA: The Company must maintain quarterly and annual EBITDA, which is defined 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 and non-cash stock-based compensation expense, less (iii) all extraordinary and non-recurring revenue and gains (including income tax benefits).
	2. Liquidity ratio: The ratio of (i) the sum of all cash on deposit with Comerica and 85% of eligible accounts receivable to (ii) all funded debt under the Comerica Agreement must be 1.15:1.00, measured on a monthly basis.
	As of December 31, 2012, the Company was in non-compliance with respect to various financial and non-financial covenants under the Comerica Agreement.  However, the Company subsequently obtained a waiver for each of the covenant violations. As of September 30, 2013, the Company was in compliance with each of the financial and non-financial covenants, except for a covenant related to permitted indebtedness for a corporate credit card account balance, for which it obtained a waiver.
	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 September 30, 2013 were as follows (in thousands):
	2013 (remaining 3 months)	$	—
	2014	6,250
	2015	7,500
	2016	1,250
	Total	15,000
	Less current portion	(4,375		)
	Noncurrent portion of debt	$	10,625
	As of September 30, 2013, the $11.9 million balance outstanding under the revolving line of credit with Comerica had a maturity date of July 26, 2014, and as a result is shown as a current liability in the accompanying condensed consolidated balance sheet.

STOCKHOLDERS_EQUITY_DEFICIT

STOCKHOLDERS' EQUITY (DEFICIT)	9 Months Ended
	Sep. 30, 2013
STOCKHOLDERS' EQUITY (DEFICIT)	'
STOCKHOLDERS' EQUITY (DEFICIT)	'
	8.                                      STOCKHOLDERS’ EQUITY (DEFICIT)
	Initial Public Offering
	In September 2013, the Company completed its 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 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 $107.9 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):
		September 30, 2013				December 31, 2012
				Shares				Shares
		Shares		Issued and		Shares		Issued and		Liquidation
		Authorized		Outstanding		Authorized		Outstanding		Preference
	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		32,807,784		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 had an expiration of 10 years from the date of issuance. As of December 31, 2012, the warrant, with an estimated fair value of $1.7 million, was classified as a liability in the accompanying consolidated balance sheet.
	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 $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 unaudited condensed 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 scheduled to expire seven years from the date of issuance. As of December 31, 2012, the warrant, with an estimated fair value of $1.1 million, was classified as a liability in the accompanying consolidated balance sheet.
	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 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 unaudited condensed 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.
	The Company recorded other expense of $2.4 million and $4.7 million for the three and nine months ended September 30, 2013, respectively, related to the fair value adjustment of the preferred stock warrant liability. The Company recorded other expense of $0.8 million and $1.1 million for the three and nine months ended September 30, 2012, respectively, related to the fair value adjustment of the warrant.
	Equity Incentive Plans
	2008 Equity Incentive Plan—The Company granted awards under its 2008 Equity Incentive Plan (the “2008 Plan”) until August 2013. The terms of the 2008 Plan provide for 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 and stock appreciation rights to the Company’s employees, directors and consultants, and the Company’s parent and subsidiary corporations’ employees and consultants. The compensation committee of the board of directors had the authority to approve the employees and other service providers to whom equity awards were granted and had the authority to determine the terms of each award, subject to the terms of the 2008 Plan, including (i) the number of shares of common stock subject to the award; (ii) when the award becomes exercisable; (iii) the option or stock appreciation right exercise price, which 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 or stock appreciation right (which may not exceed 10 years). Options granted under the 2008 Plan generally are scheduled to vest over four years, subject to continued service, and subject to certain acceleration of vesting provisions, and expire no later than 10 years from the date of grant. Restricted stock units granted under the 2008 Plan generally are scheduled to vest over four years, subject to continued service, and subject to certain acceleration of vesting provisions.  As of December 31, 2012, 14,738 shares of common stock 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 were 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 September 30, 2013 and December 31, 2012, 380,478 and 449,622 unvested shares, respectively, were subject to repurchase. During the nine months ended September 30, 2013 and year ended December 31, 2012, the Company repurchased 8,958 and 5,834 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 sentence 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.
	Stock Options
	The following table summarizes option award activity for the nine months ended September 30, 2013:
		Number of		Average			Contractual
		Shares		Exercise			Life		Aggregate
		Outstanding		Price			(Years)		Intrinsic Value
									(in thousands)
	Balance at December 31, 2012	5,832,705		$	3.65		9.1		$	44,073
	Options granted (weighted average fair value of $9.99 per share)	2,198,848		13.51
	Options exercised	(388,115	)	3.26
	Options forfeited	(238,624	)	3.93
	Balance at September 30, 2013	7,404,814		$	6.59		8.7		$	349,123
	Options vested and expected to vest - September 30, 2013	6,747,026		$	6.41		8.7		$	319,308
	Options vested and exercisable - September 30, 2013	2,372,008		$	2.72		7.9		$	121,010
	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$9.5 million and $0.5 million for the three months ended September 30, 2013 and 2012, respectively, and $10.9 million and $0.8 million for the nine months ended September 30, 2013 and 2012, respectively.  The weighted-average grant date fair value of options granted was $13.12 and $3.80 for the three months ended September 30, 2013 and 2012, respectively, and $9.99 and $2.19 for the nine months ended September 30, 2013 and 2012, respectively.
	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:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
	Expected term (years)	5.3-6.1		6.0-6.1		5.3-6.6		5.9-6.1
	Volatility	58.2%-59.1%		62.4%-62.6%		58.2%-64.9%		62.3%-62.9%
	Risk-free interest rate	1.59%-1.73%		0.91%-0.93%		1.04%-1.88%		0.85%-1.21%
	Dividend yield	—		—		—		—
	The following table summarizes the allocation of stock-based compensation and restricted stock for employees and non-employees in the accompanying consolidated statements of operations (in thousands):
		Three Months						Nine Months
		Ended						Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Cost of revenue	$	93		$	5		$	211		$	20
	Research and development	506			46			1,266			111
	Sales and marketing	1,152			100			2,471			196
	General and administrative	902			61			2,305			200
	Total(*)	$	2,653		$	212		$	6,253		$	527
	(*)                                 The table above includes the impact of the issuance of restricted stock at fair value.
The Company capitalized stock-based compensation as internally developed software costs of $0.3 million and $0 for the three months ended September 30, 2013 and 2012, respectively, and $0.4 million and $0 for the nine months ended September 30, 2013 and 2012, respectively.
As of September 30, 2013 and December 31, 2012, unamortized stock-based compensation expense related to unvested common stock options was $23.3 million and $12.5 million, respectively. The weighted-average period over which such stock-based compensation expense will be recognized is approximately 3.1 years.
Options to Nonemployees—For the three and nine months ended September 30, 2013, the Company granted options to purchase a total of 1,500 and 8,500 shares of common stock, respectively, to nonemployees. The Company did not grant any stock options to nonemployees for the year ended December 31, 2012. The definition of an employee includes a nonemployee 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 of $0 for the three months ended September 30, 2013 and 2012, respectively, and $0.1 million and $0 for the nine months ended September 30, 2013 and 2012, respectively. Options to nonemployees of 8,900 and 12,400 were outstanding as of September 30, 2013 and December 31, 2012, respectively.
Restricted Common Stock—Pursuant to restricted stock purchase agreements, the Company issued a total of 0 shares for the three months ended September 30, 2013 and 2012, respectively, 0 and 11,571 shares for the nine months ended September 30, 2013 and September 30, 2012, respectively.
Restricted Stock Units (RSUs)— During the three months ended September 30, 2013, the Company granted 51,382 RSUs. For the three and nine months ended September 30, 2013, the Company recognized stock-based compensation expense associated with the RSUs of $0.1 million. At September 30, 2013, unrecognized compensation expense related to the RSUs was $0.9 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 day of the offering period. There were no offerings of share purchase rights to employees under the Company’s ESPP for the nine months ended September 30, 2013.

NET_INCOME_LOSS_PER_SHARE

NET INCOME (LOSS) PER SHARE	9 Months Ended
	Sep. 30, 2013
NET INCOME (LOSS) PER SHARE	'
NET INCOME (LOSS) PER SHARE	'
	9.                                      NET INCOME (LOSS) PER SHARE
	The Company calculates its basic and diluted net 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. Diluted net loss per common share is computed giving effect to all potential dilutive common shares, including common stock issuable upon exercise of stock options, and unvested restricted common stock. As the Company had net losses for the three months ended September 30, 2013 and 2012, and for the nine months ended September 30, 2013 and 2012, 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):
		Three Months						Nine Months
		Ended September 30,						Ended September 30,
		2013			2012			2013			2012
	Net loss	$	(6,860	)	$	(2,002	)	$	(18,771	)	$	(4,472	)
	Weighted-average shares used to compute basic and diluted net loss per share	11,315			8,067			9,346			7,971
	Basic and diluted net loss per share	$	(0.61	)	$	(0.25	)	$	(2.01	)	$	(0.56	)
	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):
		Three Months				Nine Months
		Ended September 30,				Ended September 30,
		2013		2012		2013		2012
	Convertible preferred stock	—		19,479		—		19,479
	Employee stock options	7,405		3,261		7,405		3,261
	Shares subject to repurchase	380		436		380		436
	Restricted Stock Units (RSUs)	51		—		51		—
	Convertible preferred stock warrants	—		267		—		267
		7,836		23,443		7,836		23,443

INCOME_TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2013
INCOME TAXES	'
INCOME TAXES	'
	10.                               INCOME TAXES
	The Company is subject to income tax in the United States as well as other tax jurisdictions in which it conducts business.  Earnings from non-U.S. activities are subject to local country income tax. The Company does not provide for federal income taxes on the undistributed earnings of its foreign subsidiaries as such earnings are to be reinvested indefinitely.
	The Company recorded an income tax provision of $0.1 million and $0.1 million for the three months ended September 30, 2013 and 2012, respectively, related to foreign income taxes and state minimum taxes and $0.2 million and $0.1 million for the nine months ended September 30, 2013 and 2012, respectively. The primary difference between the effective tax rate and the federal statutory tax rate in the United States relates to the valuation allowances on the Company’s net operating losses, foreign tax rate differences, and non-deductible stock-based compensation expense.
	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 carryforwards, research and development and other tax credits, the Company has provided a full valuation allowance reserved against such assets as of September 30, 2013 and December 31, 2012.

COMMITMENTS_AND_CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2013
COMMITMENTS AND CONTINGENCIES	'
COMMITMENTS AND CONTINGENCIES	'
	11.                               COMMITMENTS AND CONTINGENCIES
	Operating Leases—The Company has operating lease agreements for office, research and development and sales and marketing space in the United States that expire at various dates, with the latest expiration date being November 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 $1.0 million and $0.5 million for the three months ended September 30, 2013 and 2012, respectively, and $2.5 million and $1.1 million for the nine months ended September 30, 2013 and 2012, respectively.
	Approximate remaining future minimum lease payments under these non-cancelable operating leases as of September 30, 2013 were as follows (in thousands):
	Year ending December 31,	Future
		Payments
	2013 (remaining 3 months)	$	862
	2014	4,164
	2015	8,869
	2016	9,028
	2017	8,555
	Thereafter	29,661
		$	61,139
	The total approximate future minimum lease payments of $61.1 million is primarily comprised of lease payments due under two operating lease agreements. The first lease is for the Company’s new sales office in New York, New York, which expires in 2024 and has future operating lease obligations of $25.0 million. The second lease is for the Company’s new headquarters facility in Redwood City, California, which expires in 2019 and has future operating lease obligations of $25.6 million.
	Letter of Credit—As of September 30, 2013 and December 31, 2012, the Company had irrevocable letters of credit outstanding in the amount of $3.0 million and $0.2 million for the benefit of a landlord related to noncancelable facilities leases. The letters of credit expire at various dates, with the latest expiration date being February 2023.
	Indemnification Agreements—In the ordinary course of business, the Company enters into agreements of varying scope and terms pursuant to which it is obligated to indemnify 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 sheet, consolidated statement of operations, consolidated statements of comprehensive loss, or consolidated statements of cash flows.
	Legal Proceedings—From time to time, the Company is subject to various legal proceedings and claims, either asserted or unasserted, that arise in the ordinary course of business. Although the outcome of the various legal proceedings and claims cannot be predicted with certainty, the Company has not had a history of outcomes to date that have been material to the statement of operations and does not currently believe that any of these proceedings or other claims will have a material adverse effect on the Company’s business, consolidated financial condition, results of operations or cash flows.

RETIREMENT_PLANS

RETIREMENT PLANS	9 Months Ended
	Sep. 30, 2013
RETIREMENT PLANS	'
RETIREMENT PLANS	'
	12.                               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	9 Months Ended
	Sep. 30, 2013
SEGMENTS	'
SEGMENTS	'
	13.                               SEGMENTS
	The Company considers operating segments to be components of the Company in 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):
		Three Months				Nine Months
		Ended September 30,				Ended September 30,
		2013		2012		2013		2012
	North America	$	56,578	$	24,062	$	137,824	$	60,580
	All Other Countries	5,880		2,840		17,215		5,914
	Total revenue	$	62,458	$	26,902	$	155,039	$	66,494
	The following table summarizes total long-lived assets in the respective locations (in thousands):
		September 30,		December 31,
		2013		2012
	North America	$	19,888	$	9,959
	All Other Countries	1,053		980
	Total long-lived assets, net	$	20,941	$	10,939
	During the three and nine months ended September 30, 2013 and 2012, no single customer represented more than 10% of revenue.

SUBSEQUENT_EVENTS

SUBSEQUENT EVENTS	9 Months Ended
	Sep. 30, 2013
SUBSEQUENT EVENTS	'
SUBSEQUENT EVENTS	'
	14.                              SUBSEQUENT EVENTS
	No subsequent events occured that would require adjustment to the financial statements or disclosures included in the financial statements.

NATURE_OF_BUSINESS_AND_SUMMARY1

NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2013
NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	'
Principles of Consolidation	'
	Principles of Consolidation—The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries, which are 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 unaudited condensed 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 unaudited condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Such estimates include, but are not limited to, provisions for doubtful accounts, the amount of software development costs which should be capitalized, future taxable income, the useful lives of long-lived assets and the assumptions used for purposes of determining stock-based compensation. Actual results could differ from those estimates.
Foreign Currency Translation	'
	Foreign Currency Translation—Each of the Company’s foreign subsidiaries records its assets, liabilities and results of operations in its local currency, which is its functional currency. The Company translates these subsidiary consolidated financial statements into U.S. dollars each reporting period for purposes of consolidation.
	Assets and liabilities of the Company’s foreign subsidiaries 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, 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, 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 term debt and line of credit approximates its recorded amount at September 30, 2013 as the interest rate on the 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 three months 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 September 30, 2013, no customer accounted for 10% or more of accounts receivable.  As of December 31, 2012, one customer accounted for 10% of accounts receivable.
	During the three and nine months ended September 30, 2013 and 2012, 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):
		Nine Months
		Ended		Year Ended
		September 30,		December 31,
		2013		2012
	Allowance for doubtful accounts:
	Balance, beginning of period	$	468	$	203
	Bad debt expense	521		285
	Recoveries (write-offs), net	19		(20		)
	Balance, end of the period	$	1,008	$	468
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 and amortization are removed from the balance sheet and any resulting gain or loss is reflected in operations in the period realized.
	Property and equipment are initially recorded at cost and depreciated using the straight-line method over the estimated useful lives of the assets. Depreciation and amortization periods for the Company’s property and equipment are as follows:
	Asset	Estimated
	Classification	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
	Leasehold improvements	Shorter of the lease term or estimated useful life
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 $4.9 million and $3.3 million in internal-use software costs during the nine months ended September 30, 2013 and 2012, 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 two to three years. Amortization expense totaled $0.9 million and $0.6 million for the three months ended September 30, 2013 and 2012, respectively, and $2.5 million and $1.6 million for the nine months ended September 30, 2013 and 2012, 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 its estimated useful life is no longer appropriate. If indicators of impairment exist and the undiscounted projected cash flows associated with such asset is less than the carrying amount of the asset, an impairment loss is recorded to write the asset down to its estimated fair value. Fair value is estimated based on discounted future cash flows. No impairment charges were recorded during the three and nine months ended September 30, 2013 and 2012.
Revenue Recognition	'
	Revenue Recognition—We generate 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; and
	·                  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 to be delivered, the agreed upon rate 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 acts as the principal in 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 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 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 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 regularly reviews 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, and is typically recognized within twelve months.
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, such as facility-related expenses, insurance, supplies and other fixed costs, associated with the Company’s engineering and research and development departments, as well as costs for contracted services and supplies. The Company reviews costs incurred in the application development stage and assesses such costs for 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, such as facility-related expenses, insurance, supplies and other fixed costs, certain advertising costs, travel, trade shows and marketing materials. The Company incurred advertising costs of $1.6 million and $0.1 million for the three months ended September 30, 2013 and 2012, respectively, and $3.3 million and $0.1 million for the nine months ended September 30, 2013 and 2012, 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.
Stock-Based Compensation	'
	Stock-Based Compensation—The Company measures compensation expense for all stock-based payment awards, including stock options and restricted stock units granted to employees, based on the estimated fair values on the date of the grant. The fair value of each stock-based payment award granted is estimated using the Black-Scholes option pricing model. Stock-based compensation is recognized on a straight-line basis over the requisite service 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 nonemployees based on the fair value of the awards determined using the Black-Scholes option pricing model. The fair value of stock options granted to nonemployees 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 sheet as of December 31, 2012. The fully vested convertible preferred stock warrants are 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 September 30, 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 carryforwards 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 carryforwards, research and development and other tax credits, the Company has provided a full valuation allowance reserved against such assets as of September 30, 2013 and December 31, 2012.
	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.
Deferred Offering Costs	'
	Deferred Offering Costs—Deferred offering costs consisted primarily of direct incremental costs related to the Company’s IPO 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, 2012.  Upon the completion of the IPO, these amounts were offset against the proceeds of the IPO.
Comprehensive Loss	'
	Comprehensive 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 three and nine months ended September 30, 2013 and 2012.
Recently Issued Accounting Pronouncements	'
	Recently Issued Accounting Pronouncements
	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 in the notes to the financial statements will still be required. 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 condensed financial statements.

NATURE_OF_BUSINESS_AND_SUMMARY2

NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	9 Months Ended
	Sep. 30, 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):
		Nine Months
		Ended		Year Ended
		September 30,		December 31,
		2013		2012
	Allowance for doubtful accounts:
	Balance, beginning of period	$	468	$	203
	Bad debt expense	521		285
	Recoveries (write-offs), net	19		(20		)
	Balance, end of the period	$	1,008	$	468
Schedule of depreciation and amortization periods for the Company's property and equipment	'
	Asset	Estimated
	Classification	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
	Leasehold improvements	Shorter of the lease term or estimated useful life

FAIR_VALUE_MEASUREMENTS_Tables

FAIR VALUE MEASUREMENTS (Tables)	9 Months Ended
	Sep. 30, 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):
	September 30, 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):
		Three Months Ended					Nine Months Ended
		September 30,					September 30,
		2013			2012		2013			2012
	Balance at beginning of period	$	5,096		$	695	$	2,741		$	433
	Changes in fair value of warrants	2,385			831		4,740			1,093
	Conversion of warrants to common stock	(7,481		)	—		(7,481		)	—
	Balance at end of period	$	—		$	1,526	$	—		$	1,526

CASH_AND_CASH_EQUIVALENTS_Tabl

CASH AND CASH EQUIVALENTS (Tables)	9 Months Ended
	Sep. 30, 2013
CASH AND CASH EQUIVALENTS	'
Schedule of cash and cash equivalents	'
	Cash and cash equivalents as of September 30, 2013 and December 31, 2012 consisted of the following (in thousands):
		September 30,		December 31,
		2013		2012
	Cash and cash equivalents
	Cash	$	122,382	$	11,996
	Money market funds	2,900		2,900
	Total cash and cash equivalents	$	125,282	$	14,896

PROPERTY_EQUIPMENT_AND_SOFTWAR1

PROPERTY, EQUIPMENT AND SOFTWARE (Tables)	9 Months Ended
	Sep. 30, 2013
PROPERTY, EQUIPMENT AND SOFTWARE	'
Schedule of property, equipment and software	'
	Property, equipment and software as of September 30, 2013 and December 31, 2012 consisted of the following (in thousands):
		September 30,			December 31,
		2013			2012
	Capitalized internal use software costs	$	15,364		$	10,441
	Computer hardware and software	12,970			4,281
	Furniture and fixtures	1,624			816
	Leasehold improvements	807			656
	Construction in progress	1,115			1,126
	Total	31,880			17,320
	Accumulated depreciation and amortization	(10,939		)	(6,381		)
	Net property, equipment and software	$	20,941		$	10,939

ACCRUED_AND_OTHER_CURRENT_LIAB1

ACCRUED AND OTHER CURRENT LIABILITIES (Tables)	9 Months Ended
	Sep. 30, 2013
ACCRUED AND OTHER CURRENT LIABILITIES	'
Schedule of accrued and other current liabilities	'
	Accrued and other current liabilities as of September 30, 2013 and December 31, 2012 consisted of the following (in thousands):
		September 30,		December 31,
		2013		2012
	Payroll and related expenses	$	7,765	$	3,357
	Accrued vacation	1,791		991
	Professional services	1,932		268
	Accrued credit cards	751		122
	Early exercise of unvested stock options	1,269		451
	Other accrued expenses	2,199		997
	Total	$	15,707	$	6,186

OTHER_INCOME_EXPENSE_NET_Table

OTHER INCOME (EXPENSE), NET (Tables)	9 Months Ended
	Sep. 30, 2013
OTHER INCOME (EXPENSE), NET	'
Schedule of other income (expense), net	'
	Other income (expense), net for the three and nine months ended September 30, 2013 and 2012 consisted of the following (in thousands):
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013			2012
	Gain (loss) on foreign translation	$	108	$	31	$	(352	)	$	31
	Other non-operating income (loss), net	47		34		139			126
	Total	$	155	$	65	$	(213	)	$	157

DEBT_Tables

DEBT (Tables)	9 Months Ended
	Sep. 30, 2013
DEBT	'
Schedule of future principal payments of long-term debt	'
	Future principal payments of long-term debt as of September 30, 2013 were as follows (in thousands):
	2013 (remaining 3 months)	$	—
	2014	6,250
	2015	7,500
	2016	1,250
	Total	15,000
	Less current portion	(4,375		)
	Noncurrent portion of debt	$	10,625

STOCKHOLDERS_EQUITY_DEFICIT_Ta

STOCKHOLDERS' EQUITY (DEFICIT) (Tables)	9 Months Ended
	Sep. 30, 2013
STOCKHOLDERS' EQUITY (DEFICIT)	'
Schedule of shares authorized, issued and outstanding	'
	The following table presents the shares authorized and issued and outstanding as of the periods presented (in thousands, except share data):
		September 30, 2013				December 31, 2012
				Shares				Shares
		Shares		Issued and		Shares		Issued and		Liquidation
		Authorized		Outstanding		Authorized		Outstanding		Preference
	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		32,807,784		35,850,100		8,680,041		—
	Undesignated preferred stock	100,000,000		—		—		—		—
Summary of option award activity	'
		Number of		Average			Contractual
		Shares		Exercise			Life		Aggregate
		Outstanding		Price			(Years)		Intrinsic Value
									(in thousands)
	Balance at December 31, 2012	5,832,705		$	3.65		9.1		$	44,073
	Options granted (weighted average fair value of $9.99 per share)	2,198,848		13.51
	Options exercised	(388,115	)	3.26
	Options forfeited	(238,624	)	3.93
	Balance at September 30, 2013	7,404,814		$	6.59		8.7		$	349,123
	Options vested and expected to vest - September 30, 2013	6,747,026		$	6.41		8.7		$	319,308
	Options vested and exercisable - September 30, 2013	2,372,008		$	2.72		7.9		$	121,010
Schedule of assumptions used to value stock-based awards granted to employees	'
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
	Expected term (years)	5.3-6.1		6.0-6.1		5.3-6.6		5.9-6.1
	Volatility	58.2%-59.1%		62.4%-62.6%		58.2%-64.9%		62.3%-62.9%
	Risk-free interest rate	1.59%-1.73%		0.91%-0.93%		1.04%-1.88%		0.85%-1.21%
	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 for employees and non-employees in the accompanying consolidated statements of operations (in thousands):
		Three Months						Nine Months
		Ended						Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Cost of revenue	$	93		$	5		$	211		$	20
	Research and development	506			46			1,266			111
	Sales and marketing	1,152			100			2,471			196
	General and administrative	902			61			2,305			200
	Total(*)	$	2,653		$	212		$	6,253		$	527
	(*)                                 The table above includes the impact of the issuance of restricted stock at fair value.

NET_INCOME_LOSS_PER_SHARE_Tabl

NET INCOME (LOSS) PER SHARE (Tables)	9 Months Ended
	Sep. 30, 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):
		Three Months						Nine Months
		Ended September 30,						Ended September 30,
		2013			2012			2013			2012
	Net loss	$	(6,860	)	$	(2,002	)	$	(18,771	)	$	(4,472	)
	Weighted-average shares used to compute basic and diluted net loss per share	11,315			8,067			9,346			7,971
	Basic and diluted net loss per share	$	(0.61	)	$	(0.25	)	$	(2.01	)	$	(0.56	)
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):
		Three Months				Nine Months
		Ended September 30,				Ended September 30,
		2013		2012		2013		2012
	Convertible preferred stock	—		19,479		—		19,479
	Employee stock options	7,405		3,261		7,405		3,261
	Shares subject to repurchase	380		436		380		436
	Restricted Stock Units (RSUs)	51		—		51		—
	Convertible preferred stock warrants	—		267		—		267
		7,836		23,443		7,836		23,443

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2013 were as follows (in thousands):
	Year ending December 31,	Future
		Payments
	2013 (remaining 3 months)	$	862
	2014	4,164
	2015	8,869
	2016	9,028
	2017	8,555
	Thereafter	29,661
		$	61,139

SEGMENTS_Tables

SEGMENTS (Tables)	9 Months Ended
	Sep. 30, 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):
		Three Months				Nine Months
		Ended September 30,				Ended September 30,
		2013		2012		2013		2012
	North America	$	56,578	$	24,062	$	137,824	$	60,580
	All Other Countries	5,880		2,840		17,215		5,914
	Total revenue	$	62,458	$	26,902	$	155,039	$	66,494
Schedule of total long-lived assets in the respective locations	'
	The following table summarizes total long-lived assets in the respective locations (in thousands):
		September 30,		December 31,
		2013		2012
	North America	$	19,888	$	9,959
	All Other Countries	1,053		980
	Total long-lived assets, net	$	20,941	$	10,939

NATURE_OF_BUSINESS_AND_SUMMARY3

NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)	1 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013
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	$29
Total gross proceeds from the offering	116,000,000	'
Aggregate net proceeds received from offering	107,900,000	'

NATURE_OF_BUSINESS_AND_SUMMARY4

NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 2) (USD $)	9 Months Ended		12 Months Ended	9 Months Ended		12 Months Ended	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
				Cash	Accounts receivable	Accounts receivable	Revenue	Revenue	Revenue	Revenue
				Credit concentration	Credit concentration	Credit concentration	Customer concentration	Customer concentration	Customer concentration	Customer concentration
				item
Concentration of credit risk	'	'	'	'	'	'	'	'	'	'
Number of financial institutions where a significant portion of cash is held	'	'	'	1	'	'	'	'	'	'
Number of major customers	'	'	'	'	'	'1	'	'	'	'
Concentration percentage	'	'	'	'	10.00%	10.00%	10.00%	10.00%	10.00%	10.00%
Changes in the allowance for doubtful accounts	'	'	'	'	'	'	'	'	'	'
Balance, beginning of period	$468	$203	$203	'	'	'	'	'	'	'
Bad debt expense	521	63	285	'	'	'	'	'	'	'
Recoveries (write-offs), net	19	'	-20	'	'	'	'	'	'	'
Balance, end of period	$1,008	'	$468	'	'	'	'	'	'	'

NATURE_OF_BUSINESS_AND_SUMMARY5

NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 3) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
	item		item
Impairment of Long-lived Assets	'	'	'	'
Impairment of long-lived assets	$0	$0	$0	$0
Revenue Recognition	'	'	'	'
Number of criteria required to be met for revenue recognition	4	'	4	'
Sales and Marketing	'	'	'	'
Advertising costs	1.6	0.1	3.3	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	'	'	'	'
Internal Use Software Development Costs	'	'	'	'
Internal-use software costs capitalized	'	'	4.9	3.3
Amortization expense	$0.90	$0.60	$2.50	$1.60
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 $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Deferred Offering Costs	'	'
Deferred offering costs included in other assets	'	$0.10
Multiple-Element Arrangements	'	'
Period during which deferred revenue is recognized	'12 months	'
Stock options granted to nonemployees | Minimum	'	'
Stock-based compensation	'	'
Period during which related services are rendered	'1 year	'
Stock options granted to nonemployees | Maximum	'	'
Stock-based compensation	'	'
Period during which related services are rendered	'4 years	'

FAIR_VALUE_MEASUREMENTS_Detail

FAIR VALUE MEASUREMENTS (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Dec. 31, 2012
					Recurring	Recurring	Recurring	Recurring	Recurring	Recurring
					Fair Value	Fair Value	Fair Value	Level 1	Level 1	Level 3
					Convertible preferred stock warrant liability	Money market funds (included in cash and cash equivalents)	Money market funds (included in cash and cash equivalents)	Money market funds (included in cash and cash equivalents)	Money market funds (included in cash and cash equivalents)	Convertible preferred stock warrant liability
Fair value measurements	'	'	'	'	'	'	'	'	'	'
Financial assets	'	'	'	'	'	$2,900	$2,900	$2,900	$2,900	'
Financial liabilities	'	'	'	'	-2,741	'	'	'	'	-2,741
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	5,096	695	2,741	433	'	'	'	'	'	'
Changes in fair value of warrants	2,385	831	4,740	1,093	'	'	'	'	'	'
Conversion of warrants to common stock	-7,481	'	-7,481	'	'	'	'	'	'	'
Balance at end of period	'	$1,526	'	$1,526	'	'	'	'	'	'

CASH_AND_CASH_EQUIVALENTS_Deta

CASH AND CASH EQUIVALENTS (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Cash and cash equivalents	'	'	'	'
Total cash and cash equivalents	$125,282	$14,896	$24,399	$5,071
Cash	'	'	'	'
Cash and cash equivalents	'	'	'	'
Total cash and cash equivalents	122,382	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 (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Property, equipment and software	'	'	'	'	'
Total	$31,880,000	'	$31,880,000	'	$17,320,000
Accumulated depreciation and amortization	-10,939,000	'	-10,939,000	'	-6,381,000
Net property, equipment and software	20,941,000	'	20,941,000	'	10,939,000
Depreciation and amortization expense, excluding amortization of internal use software costs	800,000	400,000	2,100,000	900,000	'
Capital leases	0	'	0	'	0
Capitalized internal use software costs	'	'	'	'	'
Property, equipment and software	'	'	'	'	'
Total	15,364,000	'	15,364,000	'	10,441,000
Amortization expense	900,000	600,000	2,500,000	1,600,000	'
Computer hardware and software	'	'	'	'	'
Property, equipment and software	'	'	'	'	'
Total	12,970,000	'	12,970,000	'	4,281,000
Furniture and fixtures	'	'	'	'	'
Property, equipment and software	'	'	'	'	'
Total	1,624,000	'	1,624,000	'	816,000
Leasehold improvements	'	'	'	'	'
Property, equipment and software	'	'	'	'	'
Total	807,000	'	807,000	'	656,000
Construction in progress	'	'	'	'	'
Property, equipment and software	'	'	'	'	'
Total	$1,115,000	'	$1,115,000	'	$1,126,000

ACCRUED_AND_OTHER_CURRENT_LIAB2

ACCRUED AND OTHER CURRENT LIABILITIES (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
ACCRUED AND OTHER CURRENT LIABILITIES	'	'
Payroll and related expenses	$7,765	$3,357
Accrued vacation	1,791	991
Professional services	1,932	268
Accrued credit cards	751	122
Early exercise of unvested stock options	1,269	451
Other accrued expenses	2,199	997
Total	$15,707	$6,186

OTHER_INCOME_EXPENSE_NET_Detai

OTHER INCOME (EXPENSE), NET (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
OTHER INCOME (EXPENSE), NET	'	'	'	'
Gain (loss) on foreign translation	$108	$31	($352)	$31
Other non-operating income (loss), net	47	34	139	126
Total	$155	$65	($213)	$157

DEBT_Details

DEBT (Details) (USD $)

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Jun. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Mar. 31, 2012

Feb. 28, 2013

Apr. 30, 2010

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Revolving line of credit

Revolving line of credit

Revolving line of credit

Term debt

Term debt

Term debt amended in March 2012

Term debt of credit amended in February 2013

VLL Agreement

VLL Agreement

VLL Agreement

Comerica Agreement

item

Debt

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum amount available for borrowing

'

'

'

$35,000,000

'

'

'

$3,000,000

$15,000,000

'

'

'

'

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

'

'

'

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

'

'

'LIBOR

'

'

'LIBOR

'

'

'

'

'

'

'

Applicable margin over variable rate basis (as a percent)

'

'

2.75%

'

'

4.75%

'

'

'

'

'

'

'

Repayment period of growth capital advances

'

'

'

'

'

'24 months

'

'

'

'

'

'

'

Interest rate (as a percent)

'

'

2.93%

'

2.99%

4.93%

4.99%

'

'

'

'

'

'

Amount outstanding

'

'

11,900,000

'

1,900,000

15,000,000

5,000,000

'

'

'

'

'

'

Maximum borrowing capacity under the loan agreement

'

'

'

'

'

'

'

'

'

1,000,000

'

'

'

Period of interest only monthly installments

'

'

'

'

'

'

'

'

'

'6 months

'

'

'

Number of remaining equal monthly installments

'

'

'

'

'

'

'

'

'

30

'

'

'

Fixed interest rate (as a percent)

'

'

'

'

'

'

'

'

'

13.00%

'

'

'

Principal amount outstanding under the loan

'

'

'

'

'

'

'

'

'

'

100,000

0

'

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

'

'

'

'

'

'

'

'

'

'

'30 days

'

'

Percentage of eligible receivables accounts included in the numerator of liquidity ratio

'

'

'

'

'

'

'

'

'

'

'

'

85.00%

Liquidity ratio

'

'

'

'

'

'

'

'

'

'

'

'

1.15

Future principal payments of long-term debt

'

'

'

'

'

'

'

'

'

'

'

'

'

2014

6,250,000

'

'

'

'

'

'

'

'

'

'

'

'

2015

7,500,000

'

'

'

'

'

'

'

'

'

'

'

'

2016

1,250,000

'

'

'

'

'

'

'

'

'

'

'

'

Total

15,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Less current portion

-4,375,000

-1,988,000

'

'

'

'

'

'

'

'

'

'

'

Noncurrent portion of debt

$10,625,000

$3,125,000

'

'

'

'

'

'

'

'

'

'

'

STOCKHOLDERS_EQUITY_DEFICIT_De

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

1 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

1 Months Ended

0 Months Ended

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Apr. 30, 2010

Apr. 30, 2010

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 25, 2013

Dec. 31, 2012

Sep. 25, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 25, 2013

Loan and security agreement

Agreement for obtaining line of credit

Convertible preferred stock

Series A convertible preferred stock

Series A convertible preferred stock

Series A convertible preferred stock

Series A convertible preferred stock

Series A convertible preferred stock

Series A convertible preferred stock

Series B convertible preferred stock

Series B convertible preferred stock

Series C convertible preferred stock

Series C convertible preferred stock

Series C-1 convertible preferred stock

Series C-1 convertible preferred stock

Undesignated preferred stock

Initial Public Offering

Initial Public Offering

Series A convertible preferred stock warrant

Series A convertible preferred stock warrant

Loan and security agreement

Loan and security agreement

Agreement for obtaining line of credit

Agreement for obtaining line of credit

Series A convertible preferred stock

STOCKHOLDERS' EQUITY (DEFICIT)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares of common stock sold by the entity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,000,000

'

Number of shares of common stock sold by selling stockholders

600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Issuance Price Per Share (in dollars per share)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$29

'

Total gross proceeds from the offering

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$116,000,000

'

Aggregate net proceeds received from offering

'

'

'

107,880,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

107,900,000

'

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

'

'

'

'

'

'

'

'

'

0

10,618,372

'

'

'

'

0

4,811,855

0

1,116,030

0

2,932,675

'

'

'

Shares outstanding

'

'

'

'

'

'

'

'

'

0

10,618,372

'

'

'

'

0

4,811,855

0

1,116,030

0

2,932,675

'

'

'

Common stock, Shares Authorized

1,000,000,000

1,000,000,000

'

1,000,000,000

'

35,850,100

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, Shares Issued

32,807,784

32,807,784

'

32,807,784

'

8,680,041

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock, Shares Outstanding

32,807,784

32,807,784

'

32,807,784

'

8,680,041

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Liquidation Preference

'

'

'

'

'

'

'

'

'

'

9,860,000

'

'

'

'

'

12,500,000

'

8,187,000

'

34,500,000

'

'

'

Common stock, par value (in dollars per share)

$0.00

$0.00

'

$0.00

'

$0.00

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares called by warrant

'

'

'

'

'

'

161,533

104,997

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise price of warrants (in dollars per share)

'

'

'

'

'

'

$0.93

$0.93

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expiration period of warrants

'

'

'

'

'

'

'10 years

'7 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Estimated fair value of warrants

'

'

'

'

'

'

'

'

'

'

'

4,500,000

1,700,000

2,900,000

1,100,000

'

'

'

'

'

'

'

'

'

Other expense related to the fair value adjustment of the warrant

'

$2,385,000

$831,000

$4,740,000

$1,093,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

STOCKHOLDERS_EQUITY_DEFICIT_De1

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

9 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

12 Months Ended

9 Months Ended

12 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 18, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

2013 Equity Incentive Plan

2013 Equity Incentive Plan

2013 Equity Incentive Plan

Options

Options

Options

Options

Options

Options

Options

Options

Incentive stock options

Incentive stock options

Restricted stock units (RSUs)

Options and stock appreciation rights

Options and stock appreciation rights

Maximum

2008 Equity Incentive Plan

2008 Equity Incentive Plan

2008 Equity Incentive Plan

2008 Equity Incentive Plan

2008 Equity Incentive Plan

2008 Equity Incentive Plan

2013 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%

'

'

100.00%

'

Expiration period

'

'

'

'

'

'

'

'

'

'

'10 years

'

'10 years

'

'

'10 years

Vesting period

'

'

'

'

'

'

'

'

'4 years

'

'

'

'

'4 years

'

'

Shares of common stock available for future grant

'

'

'

'

'

'

'

'

0

14,738

'

'

'

'

'

'

Number of unvested shares

'

'

'

'

'

'

'

'

380,478

449,622

'

'

'

'

'

'

Number of shares of unvested stock repurchased

'

'

'

'

'

'

'

'

8,958

5,834

'

'

'

'

'

'

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

'

'

'

'

'

'

'

'

'

'

Options granted (weighted average fair value of $9.99 per share) (in shares)

'

'

'

'

'

2,198,848

'

'

'

'

'

'

'

'

'

'

Options exercised (in shares)

'

'

'

'

'

-388,115

'

'

'

'

'

'

'

'

'

'

Options forfeited (in shares)

'

'

'

'

'

-238,624

'

'

'

'

'

'

'

'

'

'

Balance at the end of the period (in shares)

'

'

'

7,404,814

'

7,404,814

'

5,832,705

'

'

'

'

'

'

'

'

Weighted average fair value (in dollars per share)

'

'

'

$13.12

$3.80

$9.99

$2.19

'

'

'

'

'

'

'

'

'

Options vested and expected to vest (in shares)

'

'

'

6,747,026

'

6,747,026

'

'

'

'

'

'

'

'

'

'

Options vested and exercisable (in shares)

'

'

'

2,372,008

'

2,372,008

'

'

'

'

'

'

'

'

'

'

Average Exercise Price

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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

'

'

'

'

'

$3.65

'

'

'

'

'

'

'

'

'

'

Options granted (weighted average fair value of $9.99 per share) (in dollars per share)

'

'

'

'

'

$13.51

'

'

'

'

'

'

'

'

'

'

Options exercised (in dollars per share)

'

'

'

'

'

$3.26

'

'

'

'

'

'

'

'

'

'

Options forfeited (in dollars per share)

'

'

'

'

'

$3.93

'

'

'

'

'

'

'

'

'

'

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

'

'

'

$6.59

'

$6.59

'

$3.65

'

'

'

'

'

'

'

'

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

'

'

'

$6.41

'

$6.41

'

'

'

'

'

'

'

'

'

'

Options vested and exercisable (in dollars per share)

'

'

'

$2.72

'

$2.72

'

'

'

'

'

'

'

'

'

'

Contractual Life

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Balance at the beginning of the period

'

'

'

'

'

'8 years 8 months 12 days

'

'9 years 1 month 6 days

'

'

'

'

'

'

'

'

Balance at the end of the period

'

'

'

'

'

'8 years 8 months 12 days

'

'9 years 1 month 6 days

'

'

'

'

'

'

'

'

Options vested and expected to vest

'

'

'

'

'

'8 years 8 months 12 days

'

'

'

'

'

'

'

'

'

'

Options vested and exercisable

'

'

'

'

'

'7 years 10 months 24 days

'

'

'

'

'

'

'

'

'

'

Aggregate Intrinsic Value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Balance at the beginning of the period

'

'

'

'

'

$44,073,000

'

'

'

'

'

'

'

'

'

'

Balance at the end of the period

'

'

'

349,123,000

'

349,123,000

'

44,073,000

'

'

'

'

'

'

'

'

Options vested and expected to vest

'

'

'

319,308,000

'

319,308,000

'

'

'

'

'

'

'

'

'

'

Options vested and exercisable

'

'

'

121,010,000

'

121,010,000

'

'

'

'

'

'

'

'

'

'

Total intrinsic value of options exercised

'

'

'

$9,500,000

$500,000

$10,900,000

$800,000

'

'

'

'

'

'

'

'

'

STOCKHOLDERS_EQUITY_DEFICIT_De2

STOCKHOLDERS' EQUITY (DEFICIT) (Details 3) (Options, USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Summary of options outstanding and vested	'	'	'	'
Expected dividends	'	'	$0	'
Assumptions used to value stock-based awards granted to employees	'	'	'	'
Volatility, lower end (as a percent)	58.20%	62.40%	58.20%	62.30%
Volatility, higher end (as a percent)	59.10%	62.60%	64.90%	62.90%
Risk-free interest rate, lower end (as a percent)	1.59%	0.91%	1.04%	0.85%
Risk-free interest rate, higher end (as a percent)	1.73%	0.93%	1.88%	1.21%
Minimum	'	'	'	'
Assumptions used to value stock-based awards granted to employees	'	'	'	'
Expected term	'5 years 3 months 18 days	'6 years	'5 years 3 months 18 days	'5 years 10 months 24 days
Maximum	'	'	'	'
Assumptions used to value stock-based awards granted to employees	'	'	'	'
Expected term	'6 years 1 month 6 days	'6 years 1 month 6 days	'6 years 7 months 6 days	'6 years 1 month 6 days

STOCKHOLDERS_EQUITY_DEFICIT_De3

STOCKHOLDERS' EQUITY (DEFICIT) (Details 4) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Options

Options

Cost of revenue

Cost of revenue

Cost of revenue

Cost of revenue

Research and development

Research and development

Research and development

Research and development

Sales and marketing

Sales and marketing

Sales and marketing

Sales and marketing

General and administrative

General and administrative

General and administrative

General and administrative

Allocation of stock-based compensation and restricted stock for employees and non-employees

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total

$2,653,000

$212,000

$6,253,000

$527,000

'

'

$93,000

$5,000

$211,000

$20,000

$506,000

$46,000

$1,266,000

$111,000

$1,152,000

$100,000

$2,471,000

$196,000

$902,000

$61,000

$2,305,000

$200,000

Stock-based compensation capitalized in internally developed software costs

300,000

0

437,000

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unamortized stock-based compensation expense related to unvested common stock options

'

'

'

'

$23,300,000

$12,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted-average period over which stock-based compensation expense will be recognized

'

'

'

'

'3 years 1 month 6 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

STOCKHOLDERS_EQUITY_DEFICIT_De4

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

3 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Aug. 31, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Employee Stock Purchase Plan

Employee Stock Purchase Plan

Options to Nonemployees

Options to Nonemployees

Options to Nonemployees

Options to Nonemployees

Options to Nonemployees

Restricted common stock

Restricted common stock

Restricted common stock

Restricted common stock

Restricted stock units (RSUs)

Restricted stock units (RSUs)

Additional disclosure

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options granted (in shares)

'

'

'

'

'

'

1,500

'

8,500

'

'

'

'

'

'

'

'

Stock-based compensation expense

$2,653,000

$212,000

$6,253,000

$527,000

'

'

$0

$0

$100,000

$0

'

'

'

'

'

$100,000

$100,000

Options outstanding (in shares)

'

'

'

'

'

'

8,900

'

8,900

'

12,400

'

'

'

'

'

'

Number of awards issued (in shares)

'

'

'

'

'

0

'

'

'

'

'

0

0

0

11,571

51,382

'

Unrecognized compensation expense

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$900,000

$900,000

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%

'

'

'

'

'

'

'

'

'

'

'

'

NET_INCOME_LOSS_PER_SHARE_Deta

NET INCOME (LOSS) PER SHARE (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Computation of net loss per common share	'	'	'	'
Net loss (in dollars)	($6,860)	($2,002)	($18,771)	($4,472)
Weighted-average shares used to compute basic and diluted net loss per share	11,315	8,067	9,346	7,971
Basic and diluted net loss per share (in dollars per share)	($0.61)	($0.25)	($2.01)	($0.56)
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)	7,836	23,443	7,836	23,443
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	'	19,479
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)	7,405	3,261	7,405	3,261
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)	380	436	380	436
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)	51	'	51	'
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 $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
INCOME TAXES	'	'	'	'
Income tax provision related to foreign and state minimum taxes	$0.10	$0.10	$0.20	$0.10

COMMITMENTS_AND_CONTINGENCIES_1

COMMITMENTS AND CONTINGENCIES (Details)) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
			item
Operating Leases	'	'	'	'	'
Rent expense	$1,000,000	$500,000	$2,500,000	$1,100,000	'
Future minimum lease payments under non-cancelable operating leases	'	'	'	'	'
2013 (remaining 3 months)	862,000	'	862,000	'	'
2014	4,164,000	'	4,164,000	'	'
2015	8,869,000	'	8,869,000	'	'
2016	9,028,000	'	9,028,000	'	'
2017	8,555,000	'	8,555,000	'	'
Thereafter	29,661,000	'	29,661,000	'	'
Total future payments	61,139,000	'	61,139,000	'	'
Letter of Credit	'	'	'	'	'
Irrevocable letters of credit outstanding	3,000,000	'	3,000,000	'	200,000
Indemnification Agreements	'	'	'	'	'
Demands to provide indemnification	'	'	0	'	'
Number of claims under indemnification agreements	'	'	0	'	'
Future minimum lease payments	'	'	'	'	'
Number of operating lease agreements	'	'	2	'	'
Total future payments	61,139,000	'	61,139,000	'	'
Lease expiring in 2024	'	'	'	'	'
Future minimum lease payments under non-cancelable operating leases	'	'	'	'	'
Total future payments	25,000,000	'	25,000,000	'	'
Future minimum lease payments	'	'	'	'	'
Total future payments	25,000,000	'	25,000,000	'	'
Lease expiring in 2019	'	'	'	'	'
Future minimum lease payments under non-cancelable operating leases	'	'	'	'	'
Total future payments	25,600,000	'	25,600,000	'	'
Future minimum lease payments	'	'	'	'	'
Total future payments	$25,600,000	'	$25,600,000	'	'

SEGMENTS_Details

SEGMENTS (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
			item
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	$62,458	$26,902	$155,039	$66,494	'
Total long-lived assets, net	20,941	'	20,941	'	10,939
North America	'	'	'	'	'
Segments	'	'	'	'	'
Total revenue	56,578	24,062	137,824	60,580	'
Total long-lived assets, net	19,888	'	19,888	'	9,959
All Other Countries	'	'	'	'	'
Segments	'	'	'	'	'
Total revenue	5,880	2,840	17,215	5,914	'
Total long-lived assets, net	$1,053	'	$1,053	'	$980

SEGMENTS_Details_2

SEGMENTS (Details 2) (Revenue, Customer concentration)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenue | Customer concentration	'	'	'	'
Concentration of credit risk	'	'	'	'
Concentration percentage	10.00%	10.00%	10.00%	10.00%