Marin Software (MRIN) 10-K 1 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Feb. 26, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	MRIN
Entity Registrant Name	MARIN SOFTWARE INC
Entity Central Index Key	1,389,002
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		5,734,000
Entity Public Float			$ 48

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 27,544	$ 34,420
Restricted cash	1,293	1,293
Accounts receivable, net	12,237	18,761
Prepaid expenses and other current assets	3,989	3,808
Total current assets	45,063	58,282
Property and equipment, net	15,559	20,581
Goodwill	16,768	19,318
Intangible assets, net	4,475	7,325
Other non-current assets	1,504	1,587
Total assets	83,369	107,093
Current liabilities
Accounts payable	2,826	2,434
Accrued expenses and other current liabilities	10,015	8,362
Deferred revenues	459	795
Capital lease obligations	1,416	1,015
Total current liabilities	14,716	12,606
Capital lease obligations, non-current	1,687	2,381
Other long-term liabilities	4,183	4,508
Total liabilities	20,586	19,495
Commitments and contingencies (Note 15)
Stockholders' equity
Convertible preferred stock, $0.001 par value - 10,000 shares authorized, no shares issued and outstanding at December 31, 2017 and December 31, 2016, respectively
Common stock, $0.001 par value - 142,857 shares authorized, 5,729 and 5,542 shares issued, 5,729 and 5,541 outstanding at December 31, 2017 and December 31, 2016, respectively	6	6
Additional paid-in capital	291,163	286,692
Accumulated deficit	(227,704)	(196,213)
Accumulated other comprehensive loss	(682)	(2,887)
Total stockholders' equity	62,783	87,598
Total liabilities and stockholders' equity	$ 83,369	$ 107,093

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Convertible preferred stock, par value	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	10,000,000	10,000,000
Convertible preferred stock, shares issued	0	0
Convertible preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	142,857,000	142,857,000
Common stock, shares issued	5,729,000	5,542,000
Common stock, shares outstanding	5,729,000	5,541,000

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues, net	$ 74,991,000	$ 99,878,000	$ 108,530,000
Cost of revenues	32,520,000	35,203,000	40,137,000
Gross profit	42,471,000	64,675,000	68,393,000
Operating expenses
Sales and marketing	26,936,000	32,889,000	45,132,000
Research and development	26,564,000	27,841,000	33,318,000
General and administrative	16,444,000	19,890,000	22,391,000
Impairment of goodwill	2,797,000	0	0
Total operating expenses	72,741,000	80,620,000	100,841,000
Loss from operations	(30,270,000)	(15,945,000)	(32,448,000)
Interest expense, net	(137,000)	(129,000)	(118,000)
Other (expenses) income, net	(77,000)	998,000	222,000
Loss before provision for income taxes	(30,484,000)	(15,076,000)	(32,344,000)
Provision for income taxes	(1,007,000)	(1,404,000)	(1,005,000)
Net loss	(31,491,000)	(16,480,000)	(33,349,000)
Foreign currency translation adjustments	2,205,000	(1,110,000)	(1,030,000)
Comprehensive loss	$ (29,286,000)	$ (17,590,000)	$ (34,379,000)
Net loss per share available to common stockholders, basic and diluted	$ (5.59)	$ (3.01)	$ (6.38)
Weighted-average shares used to compute net loss per share available to common stockholders, basic and diluted	5,638	5,474	5,225
Amortization of intangible assets is allocated as follows (Note 6):
Amortization of intangible assets	$ 2,850,000	$ 3,080,000	$ 3,134,000
Cost of Revenues [Member]
Stock-based compensation is allocated as follows (Note 11):
Allocation of stock-based compensation	822,000	1,314,000	1,171,000
Amortization of intangible assets is allocated as follows (Note 6):
Amortization of intangible assets	971,000	1,027,000	1,033,000
Restructuring related expenses are allocated as follows (Note 4):
Restructuring related expenses	0	184,000	173,000
Sales and Marketing [Member]
Stock-based compensation is allocated as follows (Note 11):
Allocation of stock-based compensation	827,000	1,281,000	2,537,000
Amortization of intangible assets is allocated as follows (Note 6):
Amortization of intangible assets	877,000	934,000	921,000
Restructuring related expenses are allocated as follows (Note 4):
Restructuring related expenses	0	348,000	718,000
Research and Development [Member]
Stock-based compensation is allocated as follows (Note 11):
Allocation of stock-based compensation	1,996,000	4,989,000	7,518,000
Amortization of intangible assets is allocated as follows (Note 6):
Amortization of intangible assets	969,000	1,027,000	1,034,000
Restructuring related expenses are allocated as follows (Note 4):
Restructuring related expenses	0	44,000	53,000
General and Administrative [Member]
Stock-based compensation is allocated as follows (Note 11):
Allocation of stock-based compensation	1,059,000	2,711,000	4,393,000
Amortization of intangible assets is allocated as follows (Note 6):
Amortization of intangible assets	33,000	92,000	146,000
Restructuring related expenses are allocated as follows (Note 4):
Restructuring related expenses	$ 0	$ 20,000	$ 270,000

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balance at Dec. 31, 2014	$ 106,117	$ 5	$ 253,251	$ (146,392)	$ (747)
Beginning Balance, shares at Dec. 31, 2014		5,026
Issuance of common stock from exercise of vested stock options, vesting of restricted stock units and vesting of options and shares subject to repurchase (Note 10)	$ 2,014	$ 0	2,014	0	0
Issuance of common stock from exercise of vested stock options, vesting of restricted stock units and vesting of options and shares subject to repurchase (Note 10), shares	104	192
Tax withholding related to vesting of restricted stock units	$ (571)	$ 0	(571)	0	0
Issuance of common stock under employee stock purchase plan	1,035	$ 0	1,035	0	0
Issuance of common stock under employee stock purchase plan, shares		37
Issuance of unrestricted common stock in connection with acquisition of SocialMoov S.A.S.	4,338	$ 0	4,338	0	0
Issuance of unrestricted common stock in connection with acquisition of SocialMoov S.A.S., shares		91
Stock issuance costs incurred in connection with acquisition of SocialMoov S.A.S.	(51)	$ 0	(51)	0	0
Stock-based compensation expense	15,619	0	15,619	0	0
Repurchase of unvested shares	(2)	$ 0	(2)	0	0
Repurchase of unvested shares, shares		0
Stock-based compensation tax benefits	3	$ 0	3	0	0
Net loss	(33,349)	0	0	(33,349)	0
Foreign currency translation adjustments and other, net	(1,022)	0	0	8	(1,030)
Ending Balance at Dec. 31, 2015	94,131	$ 5	275,636	(179,733)	(1,777)
Ending Balance, shares at Dec. 31, 2015		5,346
Issuance of common stock from exercise of vested stock options, vesting of restricted stock units and vesting of options and shares subject to repurchase (Note 10)	$ 570	$ 1	569	0	0
Issuance of common stock from exercise of vested stock options, vesting of restricted stock units and vesting of options and shares subject to repurchase (Note 10), shares	38	87
Tax withholding related to vesting of restricted stock units	$ (362)	$ 0	(362)	0	0
Issuance of common stock under employee stock purchase plan	548	$ 0	548	0	0
Issuance of common stock under employee stock purchase plan, shares		42
Issuance of unrestricted common stock in connection with acquisition of SocialMoov S.A.S.	0	$ 0	0	0	0
Issuance of unrestricted common stock in connection with acquisition of SocialMoov S.A.S., shares		66
Stock-based compensation expense	10,295	$ 0	10,295	0	0
Net loss	(16,480)	0	0	(16,480)	0
Foreign currency translation adjustments and other, net	(1,104)	0	6	0	(1,110)
Ending Balance at Dec. 31, 2016	87,598	$ 6	286,692	(196,213)	(2,887)
Ending Balance, shares at Dec. 31, 2016		5,541
Issuance of common stock from exercise of vested stock options, vesting of restricted stock units and vesting of options and shares subject to repurchase (Note 10)	11	$ 0	11	0	0
Issuance of common stock from exercise of vested stock options, vesting of restricted stock units and vesting of options and shares subject to repurchase (Note 10), shares		79
Tax withholding related to vesting of restricted stock units	(604)	$ 0	(604)	0	0
Issuance of common stock under employee stock purchase plan	362	$ 0	362	0	0
Issuance of common stock under employee stock purchase plan, shares		43
Issuance of unrestricted common stock in connection with acquisition of SocialMoov S.A.S.	0	$ 0	0	0	0
Issuance of unrestricted common stock in connection with acquisition of SocialMoov S.A.S., shares		66
Stock-based compensation expense	4,704	$ 0	4,704	0	0
Net loss	(31,491)	0	0	(31,491)	0
Foreign currency translation adjustments and other, net	2,203	0	(2)	0	2,205
Ending Balance at Dec. 31, 2017	$ 62,783	$ 6	$ 291,163	$ (227,704)	$ (682)
Ending Balance, shares at Dec. 31, 2017		5,729

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating activities
Net loss	$ (31,491,000)	$ (16,480,000)	$ (33,349,000)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities
Impairment of goodwill	2,797,000	0	0
Depreciation	4,758,000	6,035,000	6,993,000
Amortization of internally developed software	3,669,000	2,988,000	2,550,000
Amortization of intangible assets	2,850,000	3,080,000	3,134,000
(Gain) loss on disposal of property and equipment	(11,000)	(3,000)	19,000
Unrealized foreign currency losses (gains)	986,000	(419,000)	(216,000)
Non-cash interest expense related to debt agreements	15,000	27,000	42,000
Stock-based compensation related to equity awards and restricted stock	4,704,000	10,295,000	15,619,000
Provision for bad debts	1,507,000	2,328,000	1,210,000
Deferred income tax benefits	(358,000)	(305,000)	(177,000)
Excess tax benefits from stock-based award activities	0	0	(3,000)
Payment of contingent consideration for prior acquisition	0	(93,000)	0
Changes in operating assets and liabilities, net of effect of acquisition
Accounts receivable	4,754,000	795,000	(2,986,000)
Prepaid expenses and other current assets	(268,000)	546,000	575,000
Other assets	(42,000)	(346,000)	348,000
Accounts payable	306,000	741,000	(1,597,000)
Deferred revenues	(346,000)	(628,000)	(625,000)
Accrued expenses and other liabilities	1,300,000	(2,480,000)	1,953,000
Net cash (used in) provided by operating activities	(4,870,000)	6,081,000	(6,510,000)
Investing activities
Purchases of property and equipment	(461,000)	(1,207,000)	(8,584,000)
Proceeds from disposal of property and equipment	11,000	5,000	0
Capitalization of internally developed software	(2,068,000)	(4,712,000)	(5,568,000)
Acquisition of business, net of cash acquired	0	0	(7,738,000)
Net cash used in investing activities	(2,518,000)	(5,914,000)	(21,890,000)
Financing activities
Repayments of capital lease obligations and other debt agreements	(1,160,000)	(1,436,000)	(3,649,000)
Debt issuance costs	0	0	(53,000)
Repurchases of unvested shares	0	0	(2,000)
Employee taxes paid for withheld shares upon equity award settlement	(604,000)	(362,000)	(571,000)
Proceeds from exercises of common stock options	0	390,000	1,439,000
Proceeds from employee stock purchase plan, net	312,000	663,000	968,000
Excess tax benefits from stock-based award activities	0	0	3,000
Net cash used in financing activities	(1,452,000)	(745,000)	(1,865,000)
Effect of foreign exchange rate changes on cash and cash equivalents and restricted cash	1,964,000	(1,035,000)	(662,000)
Net decrease in cash and cash equivalents and restricted cash	(6,876,000)	(1,613,000)	(30,927,000)
Beginning of year	35,713,000	37,326,000	68,253,000
End of year	28,837,000	35,713,000	37,326,000
Supplemental disclosures of other cash flow information
Cash paid for interest	210,000	189,000	106,000
Cash paid for income taxes	1,491,000	728,000	404,000
Supplemental disclosure of non-cash investing and financing activities
Acquisition of equipment through capital leases	852,000	1,864,000	2,350,000
Purchases of property and equipment recorded in accounts payable and accrued expenses	30,000	5,000	0
Issuance of common stock under employee stock purchase plan	362,000	548,000	1,035,000
Issuance of common stock in connection with acquisition of business	$ 0	$ 0	$ 4,338,000

Background

Background	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Background	1. Background Marin Software Incorporated (the “Company”) was incorporated in Delaware in March 2006. The Company provides a leading cross-channel, cross-device, enterprise marketing software platform for search, social and display advertising channels, offered as a software-as-a-service, or SaaS, solution for advertisers and agencies. The Company’s platform enables digital marketers to improve financial performance, realize efficiencies and time savings, and make better business decisions. The Company’s corporate headquarters are located in San Francisco, California, and the Company has additional offices in the following locations: Austin, Chicago, Dublin, Hamburg, London, New York, Paris, Portland, Shanghai, Sydney and Tokyo. References to “2017,” “2016” and “2015” shall mean the year ended December 31, 2017, the year ended December 31, 2016 and the year ended December 31, 2015, respectively. All amounts presented in these notes to the consolidated financial statements are in thousands, except where noted.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Liquidity The Company has incurred significant losses in each fiscal year since its incorporation in 2006 and management expects such losses to continue over the next several years. The Company experienced net losses of $31,491, $16,480 and $33,349 during 2017, 2016 and 2015, respectively. As of December 31, 2017, the Company had an accumulated deficit of $227,704. The Company had cash, cash equivalents and restricted cash of $28,837 as of December 31, 2017. Management expects to incur additional losses and experience negative cash flows in the future. To continue to fund operations, including research and development, the Company will need to increase revenues, lower costs and/or raise additional capital. The Company believes that its cash, cash equivalents and restricted cash will provide sufficient funds for the Company to continue as a going concern for at least 12 months from the date of issuance of these consolidated financial statements. Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated upon consolidation. Reclassifications When necessary, reclassifications have been made to prior period financial information to conform to the current year presentation. Reverse Stock Split and Reduction in Authorized Shares On October 5, 2017, the Company effected a reverse stock split of its outstanding common stock. As a result of the reverse stock split, each seven outstanding shares of the Company’s common stock were combined into one outstanding share of common stock, without any change in par value. The common stock began trading on the New York Stock Exchange on a split-adjusted basis on October 6, 2017. No fractional shares were issued in connection with the reverse stock split and the Company paid in cash the fair value of such fractional shares. On October 5, 2017, the Company also effected a reduction in the Company’s authorized shares of common stock, from 500,000 shares to 142,857 shares. There was no change to the number of authorized shares of convertible preferred stock, which remained at 10,000 shares. All share and per share amounts of the Company’s common stock, as well as stock options and restricted stock units (“RSUs”), included in the accompanying consolidated financial statements have been adjusted to give effect to the reverse stock split for all periods presented. In addition, as a result of the reverse stock split, the Company reclassified an amount equal to the reduction in common stock at par value to additional paid-in capital on its consolidated balance sheets. Accounting Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States (“GAAP”) requires management to make certain estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company is subject to uncertainties such as the impact of future events, economic and political factors and changes in the Company’s business environment; therefore, actual results could differ from these estimates. Accordingly, the accounting estimates used in the preparation of the Company’s financial statements will change as new events occur, as more experience is acquired, as additional information is obtained and as the Company’s operating environment changes. Changes in estimates are made when circumstances warrant. Such changes in estimates and refinements in estimation methodologies are reflected in reported results of operations and if material, the effects of changes in estimates are disclosed in the notes to the consolidated financial statements. Significant estimates and assumptions by management affect the allowances for doubtful accounts and customer credits, the carrying value of long-lived assets (including goodwill and intangible assets), the useful lives of long-lived assets, the accounting for income taxes, and stock-based compensation. Certain Significant Risks and Uncertainties The Company operates in a rapidly changing environment that involves a number of risks, some of which are beyond the Company’s control that could have a material adverse effect on the Company’s business, operating results, and financial condition. These risks include, among others, the Company’s history of losses and negative cash flows; the highly competitive environment in which the Company operates; the ability to maintain and increase usage rate of the Company’s platform and the ability for the Company to increase demand for its solutions. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist of cash, cash equivalents and accounts receivable. The Company’s cash and cash equivalents are placed with high-credit-quality financial institutions and issuers, and at times exceed federally insured limits. The Company has not experienced any loss relating to cash and cash equivalents in these accounts. The Company performs periodic credit evaluations of its customers and generally does not require collateral. As of December 31, 2017 and 2016, no single customer accounted for 10% or more of net accounts receivable. No single customer accounted for 10% or more of consolidated revenues, net during the years ended December 31, 2017, 2016 and 2015. Cash and Cash Equivalents and Restricted Cash The Company considers all highly liquid investments with an original or remaining maturity from the Company’s date of purchase of 90 days or less to be cash equivalents. Deposits held with financial institutions are likely to exceed the amount of insurance on these deposits. Cash equivalents consist of money market funds, which are readily convertible into cash and have original maturity dates of less than three months from the date of their respective purchases. Cash equivalents were $8,831 and $15,657 as of December 31, 2017 and 2016, respectively. Restricted cash consists of deposits held with a financial institution to secure the Company’s non-cancelable lease for its corporate headquarters in San Francisco (see Note 8). Fair Value of Financial Instruments The Company’s financial instruments, including accounts receivable, accounts payable and accrued expenses are carried at cost, which approximates fair value because of the short-term nature of those instruments. Based on borrowing rates available to the Company for loans with similar terms and maturities, and in consideration of the Company’s credit risk profile, the carrying value of outstanding capital lease obligations (Note 8) approximates fair value (level 2 within the fair value hierarchy). The Company measures and reports certain financial assets at fair value on a recurring basis, including its investments in money market funds. The fair value hierarchy prioritizes the inputs into three broad levels: Level 1 Inputs are unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 Inputs are quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument. Level 3 Inputs are unobservable inputs based on the Company’s assumptions. A financial instrument’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. Allowance for Doubtful Accounts and Revenue Credits The allowance for doubtful accounts reflects the Company’s best estimate of probable losses inherent in the Company’s receivables portfolio determined on the basis of historical experience, specific allowances for known troubled accounts and other currently available evidence. The Company has not experienced significant credit losses from its accounts receivable. The Company performs a regular review of its customers’ payment histories and associated credit risks and it does not require collateral from its customers. Certain contracts with advertising agencies contain sequential liability provisions, whereby the agency does not have an obligation to pay the Company until payment is received from the agency’s customers. In these circumstances, the Company evaluates the credit worthiness of the agency’s customers, in addition to the agency itself. The following are changes in the allowance for doubtful accounts during 2017, 2016 and 2015, respectively. Years Ended December 31, 2017 2016 2015 Balances at beginning of year $ 3,510 $ 2,188 $ 989 Additions to expense 1,507 2,328 1,210 Additions against goodwill — — 442 Write-offs and other deductions (989 ) (1,006 ) (453 ) Balances at end of year $ 4,028 $ 3,510 $ 2,188 From time to time, the Company provides credits to customers and an allowance is made based on historical credit activity. As of December 31, 2017 and 2016, the Company recorded an allowance for potential customer credits in the amount of $799 and $1,947, respectively. Property and Equipment Property and equipment are stated at historical cost less accumulated depreciation and amortization. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the related assets. Upon retirement or sale, the cost and related accumulated depreciation are removed from the balance sheet and the resulting gain or loss is reflected in operations. Major additions and improvements are capitalized while repairs and maintenance that do not extend the life of the asset are charged to operations as incurred. Depreciation and amortization expense is allocated to both cost of revenues and operating expenses. Internally Developed Software Costs incurred in the development phase are capitalized and amortized over the product’s estimated useful life, which is three years. The Company expenses all costs incurred that relate to planning and post implementation phases of development. Capitalized costs related to internally developed software under development are treated as construction in progress until the program, feature or functionality is ready for its intended use, at which time amortization commences. For 2017, 2016 and 2015, the Company capitalized $2,068, $4,712, and $5,568 of costs related to internally developed software, respectively. Amortization of capitalized costs related to internally developed software was $3,669, $2,988, and $2,550 for 2017, 2016 and 2015, respectively. As of December 31, 2017 and 2016, unamortized internally developed software costs totaled $8,617 and $10,218, respectively. Amortization of internally developed software is reflected in cost of revenues. Costs associated with minor enhancements and maintenance are expensed as incurred. Goodwill, Intangible Assets and Impairment Assessments Goodwill represents the excess of the purchase price in a business combination over the fair value of net tangible and intangible assets acquired. Intangible assets that are not considered to have an indefinite useful life are amortized over their useful lives, which range from two to six years. Estimated remaining useful lives of purchased intangible assets are evaluated to assess whether events or changes in circumstances warrant a revision to the remaining periods of amortization. The Company evaluates goodwill for impairment in the fourth quarter of its fiscal year annually, or more frequently if events or changes in circumstances indicate that these assets may be impaired. For the purposes of impairment testing, the Company has determined that it has one reporting unit. The Company performs its goodwill impairment test using the simplified method, whereby the fair value of this reporting unit is compared to its carrying value. If the fair value of the reporting unit exceeds the carrying value of the net assets assigned to that reporting unit, goodwill is not considered impaired. If the carrying value of the net assets assigned to the reporting unit exceeds the fair value of the reporting unit, then goodwill is considered impaired by an amount equal to that difference. In the first half of 2017, the market capitalization of the Company’s common stock sustained a significant decline so that it fell below the book value of the Company’s net assets, triggering management to conduct an interim goodwill impairment test at that time. The outcome of this goodwill impairment test resulted in an impairment of goodwill of $2,797, which was recorded in the consolidated financial statements during the three months ended June 30, 2017. Refer to Note 6 for further details of the Company’s goodwill impairment assessment. In the second half of 2017, the market capitalization of the Company’s common stock rose above the book value of the Company’s net assets. Management considered that, along with other possible factors affecting the assessment of the Company’s reporting unit for the purposes of performing a goodwill impairment assessment, including management assumptions about expected future revenue forecasts and discount rates, changes in the overall economy, trends in the stock price, any estimated control premium and other operating conditions. Ultimately, no goodwill impairment triggering events were identified in any period subsequent to June 30, 2017, including the Company’s annual goodwill impairment test in the fourth quarter. It is reasonably possible that the Company will not be able to achieve its goals of growing revenues and generating positive cash flows by increasing its customer base and reducing customer turnover. If this were the case, it could result in a further decline in the market capitalization of the Company’s common stock and lead to additional goodwill impairment triggering events. If the Company determines that its goodwill is impaired, it would be required to record a non-cash charge that may or may not be material to its consolidated financial statements. Impairment of Long-Lived Assets The Company evaluates long-lived assets, excluding goodwill, for potential impairment whenever adverse events or changes in circumstances or business climate indicate that expected undiscounted future cash flows related to such long-lived assets may not be sufficient to support the net book value of such assets. An impairment loss is recognized only if the carrying value of a long-lived asset or asset group is not recoverable and exceeds its fair value. The carrying value of a long-lived asset or asset group is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. There were no such impairment losses during 2017, 2016 or 2015. Operating Leases The Company’s operating lease agreements include provisions for tenant improvement allowances, certain rent holidays and escalations in the base price of the rent payment. The Company defers tenant improvement allowances and amortizes the balance as a reduction to rent expense over the lease term. The Company records rent holidays and rent escalations on a straight-line basis over the lease term. Deferred rent is included in accrued expenses and other current liabilities, as well as other long-term liabilities in the accompanying consolidated balance sheets. Revenue Recognition The Company generates revenues principally from subscriptions either directly with advertisers or with advertising agencies to its platform for the management of search, social and display advertising. The Company’s subscription agreements are generally one year or longer in length. The Company’s subscription fee under most contracts is variable based on the value of the advertising spend that the Company’s advertisers manage through the Company’s platform and is generally invoiced on a monthly basis. Contracts with direct advertisers and certain contracts with independent advertising agencies also include a minimum monthly fee that is payable over the duration of the contract. The Company’s customers do not have the right to take possession of the software supporting the application service at any time, nor do the arrangements contain general rights of return. The Company commences revenue recognition for both direct advertisers and advertising agencies when all of the following conditions are met: • persuasive evidence of an arrangement exists; • the Company’s platform is made available to the customer; • the fee is fixed or determinable, and; • collection is reasonably assured. The Company recognizes the total minimum fee for both direct advertisers and independent advertising agencies, where applicable, over the duration of the contract, commencing on the date that the Company’s platform is made available to the customer, provided revenues recognized do not exceed amounts that are invoiced and due. The variable fee, which is based on a percentage of the value of the advertising spend managed through the Company’s platform, is recognized once the amount is fixed or determinable, which is generally on a monthly basis concurrent with the issuance of the customer invoice. Signed contracts are used as evidence of an arrangement. The Company assesses collectability based on a number of factors such as past collection history with the customer and creditworthiness of the customer. Certain agreements with advertising agencies also contain sequential liability provisions, which provide that the agency has no obligation to pay the Company until the agency receives payment from its customers. In these circumstances, the Company evaluates the credit worthiness of the agency’s customers, in addition to the agency itself, to conclude whether or not collectability is reasonably assured. If the Company determines collectability is not reasonably assured, the Company defers the revenue recognition until collectability becomes reasonably assured. The Company applies the authoritative accounting guidance regarding revenue recognition for arrangements with multiple deliverables. Professional services and training, when sold with the Company’s platform subscription services, are accounted for separately when those services have standalone value. In determining whether professional services and training services can be accounted for separately from subscription services, the Company considers the following factors: availability of the services from other vendors; the nature of the services; the dependence of the subscription services on the customer’s decision to buy the professional services; and whether the Company sells the Company’s subscription services without professional services. If the deliverables have stand-alone value, the Company accounts for each deliverable separately and revenues are recognized for the respective deliverables as they are delivered. If one or more of the deliverables do not have stand-alone value, the deliverables that do not have stand-alone value are combined with the final deliverables within the arrangement and treated as a single unit of accounting. Revenues for arrangements treated as a single unit of accounting are recognized over the period of the contract commencing upon delivery of the final deliverable. As of December 31, 2017, the Company did not have stand-alone value for the professional services and training services. This is because the Company includes professional services and training services with the Company’s subscription services and those services are not available from other vendors. Cost of Revenues Cost of revenues primarily consists of costs related to hosting the Company’s cloud-based platform, providing implementation and ongoing customer support, data communications expenses, salaries and benefits of operations and support personnel, software license fees, costs associated with website development activities, indirect overhead, amortization expense associated with capitalized internally developed software and intangible assets and property and equipment depreciation. Stock-Based Compensation Expense Stock-based compensation expense is measured at grant date based on the fair value of the award and is expensed on a straight-line basis over the requisite service period. Fair values of stock option awards are determined on the date of grant using the Black-Scholes option-pricing model. In applying this option-pricing model, the Company’s determination of the fair value of the stock option award on the date of grant is affected by the Company’s fair value of its common stock, as well as assumptions regarding a number of subjective variables. These variables include, but are not limited to, the Company’s expected stock price volatility and the optionholders’ actual and projected stock option exercise and employment termination behaviors. RSUs are measured based on the fair market values of the underlying common stock on the dates of grant. Shares of common stock are issued on the vesting dates. For stock option and RSU awards with time-based vesting, the Company recognizes stock-based compensation expense over the requisite service period using the straight-line method, based on awards ultimately expected to vest. The Company estimates future forfeitures at the date of grant and revises the estimates, if necessary, in subsequent periods if actual forfeitures differ from those estimates. See Note 10 and Note 11 for further information. Research and Development Research and development costs are expensed as incurred, except for certain internal software development costs, which may be capitalized as noted above. Research and development costs include salaries, stock-based compensation expense, benefits and other operating costs such as outside services, supplies and allocated overhead costs. Advertising and Promotion Advertising and promotional costs are expensed as incurred and included in sales and marketing expense in the accompanying consolidated statements of comprehensive loss. Advertising and promotion expense totaled $758, $876, and $1,000 for 2017, 2016 and 2015, respectively. Sales Taxes Sales and other taxes collected from customers and remitted to governmental authorities are presented on a net basis and thus excluded from revenues. Foreign Currency For international subsidiaries whose functional currency is not the United States Dollar, we re-measure the monetary assets and liabilities of these subsidiaries to United States Dollars using rates of exchange in effect at the balance sheet date. Nonmonetary assets and liabilities are re-measured to United States Dollars using historical exchange rates, and other accounts are re-measured using average exchange rates in effect during each period presented. The effects of foreign currency translation adjustments are included in stockholders’ equity as a component of accumulated other comprehensive loss on the accompanying consolidated balance sheets, and related periodic movements are summarized as a line item in the consolidated statements of comprehensive loss. The Company records net gains and losses resulting from foreign exchange transactions as a component of other income (expenses), net. Aggregate foreign currency (losses) gains included in determining net loss were $(1,029), $(3) and $256 during 2017, 2016 and 2015, respectively. Income Taxes The Company accounts for income taxes using the asset and liability method. Under this method, deferred tax assets and liabilities are determined based on differences between the financial statement and tax basis of assets and liabilities and net operating loss and credit carryforwards using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized. The Company accounts for uncertain tax positions using a more-likely-than-not threshold for financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. The Company establishes a liability for tax-related uncertainties based on estimates of whether, and the extent to which, additional taxes will be due. The Company records an income tax liability, if any, for the difference between the benefit recognized and measured and the tax position taken or expected to be taken on the Company’s tax returns. To the extent that the assessment of such tax positions changes, the change in estimate is recorded in the period in which the determination is made. The liability is adjusted in light of changing facts and circumstances, such as the outcome of a tax audit. The provision for income taxes includes changes to the liabilities that are considered appropriate. The Company would recognize interest and penalties related to uncertain tax positions as income tax expense, though no such amounts were recognized in 2017, 2016 or 2015. As the Company maintained a full valuation allowance against its deferred tax assets in the United States, the adjustments resulted in no additional tax expense in 2017. The Company does not expect that changes in the liability for uncertain tax positions for the next twelve months will have a material impact on the Company’s consolidated financial position or results of operations. See Note 12 for information related to the enactment of the Tax Cuts and Jobs act in December 2017. Out of Period Adjustment During the year ended December 31, 2017, the Company recorded an out-of-period adjustment to correct previously overstated revenues related to its display product offering. These overstated revenues had accumulated since the Company’s acquisition in June 2014 of NowSpots, Inc., which conducted business as Perfect Audience, and the out-of-period adjustment resulted in a decrease to revenues in the amount of $400 for the year ended December 31, 2017. Management determined that this adjustment was not material to the Company’s consolidated financial statements for the year ended December 31, 2017, nor to any previously issued consolidated financial statements. Recent Accounting Pronouncements Adopted in 2017 In January 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2017-04, Intangibles – Goodwill and Other: Simplifying the Accounting for Goodwill Impairment In March 2016, the FASB issued ASU 2016-09, Compensation - Stock Compensation: Improvements to Employee Share-Based Payment Accounting Recent Accounting Pronouncements Not Yet Effective In May 2017, the FASB issued ASU 2017-09, Compensation – Stock Compensation In February 2016, the FASB issued ASU 2016-02, Leases In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers The Company will adopt the new guidance on January 1, 2018 using the modified retrospective approach, which will result in an adjustment to accumulated deficit for the cumulative effect of applying this standard to contracts in process as of the adoption date. Under this approach, the Company will not revise the prior financial statements presented, but will provide additional disclosures of the amount by which each financial statement line item is affected in the current reporting period during 2018 as a result of applying the new revenue guidance. This will include a qualitative explanation of the significant changes between the reported results under the revenue standard and the previous guidance. The Company has substantially completed its assessment of the potential impact this guidance will have on its consolidated financial statements and related disclosures. Based on that assessment, the Company currently expects the most significant impact of this new guidance will be the capitalization of costs to both obtain and fulfill contracts, which are expected to result in adjustments of approximately $1,800 and $900, respectively, to decrease the opening balance of Accumulated deficit upon adoption. Under previous accounting guidance, these costs were expensed as incurred. The Company also expects to begin recognizing breakage revenues from its arrangements with customers that prepay their advertising spend via credit card, based on historical breakage percentages. The Company does not expect the new guidance to have any further impact on its subscription revenues, as the identified performance obligations are substantially comparable to the deliverables and units of accounts identified under previous guidance.

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Business Combinations	3. Business Combinations The Company accounts for business combinations using the acquisition method of accounting in which the tangible and identifiable intangible assets and liabilities of each acquired company are recorded at their respective estimated fair values as of each acquisition date, including an amount for goodwill representing the difference between the respective purchase price and fair values of identifiable net assets. Best estimates and assumptions are used in the purchase price allocation process to accurately value assets acquired and liabilities assumed at the business combination date. These estimates and assumptions are inherently uncertain and subject to change. As a result, during the measurement period, which may be up to one year from the business combination date, the Company may record adjustments to the assets acquired and liabilities assumed with the corresponding adjustment to goodwill. After the measurement period, adjustments are recorded in the operating results in the period in which the adjustments were determined. SocialMoov S.A.S. On February 12, 2015, pursuant to the terms of a Share Purchase Agreement, the Company acquired all outstanding shares of capital stock of SocialMoov S.A.S. (“SocialMoov”), with SocialMoov surviving as a wholly owned subsidiary of the Company. Based in Paris, France, SocialMoov is a provider of social advertising tools for advertisers and agencies. In 2016, the Company completed the valuation of the fair values of the acquired tangible and identifiable intangible assets and liabilities assumed at the acquisition date, and the results of operations and the fair values of the assets acquired and liabilities assumed have been included in the consolidated financial statements since the acquisition date. The total purchase price for the acquisition was $13,288, which consisted of 91 shares of the Company’s common stock valued at $4,337 upon the closing date using the weighted average of the Company’s closing date stock price for a short period of time preceding the closing date of the acquisition, $8,858 in cash and $93 in cash paid as contingent consideration in 2016. Of the total purchase price, $2,006 was attributed to the fair value of net liabilities assumed, $1,120 was cash acquired, and $6,140 was the fair value of intangible assets acquired, with $8,034 as residual goodwill. The goodwill is primarily attributable to synergies expected to arise from the acquisition and is not deductible for tax purposes. In addition, the Company agreed to issue 132 shares of common stock, valued at $6,487 upon the closing date of the acquisition using the Company’s closing date stock price immediately preceding the acquisition, to existing employee shareholders of SocialMoov in connection with the acquisition, which were conditioned upon such employees’ continuous employment with the Company. These shares were excluded from the purchase consideration and were recognized as post-acquisition stock-based compensation expense over the employees’ requisite service periods. The Company issued half of these shares in February 2016 and the remaining half in February 2017. The Company also granted RSUs representing 31 shares of common stock, valued at $959 using the Company’s grant date stock price, with time-based vesting to employees of SocialMoov that continued employment with the Company subsequent to the acquisition. The Company recognizes compensation expense equal to the grant date fair value of the common stock or stock-based awards on a straight-line basis over the employees’ requisite service periods. The following table summarizes the fair values of tangible assets acquired, liabilities assumed, intangible assets and residual goodwill from the acquisition of SocialMoov (in thousands, except years): Estimated Fair Value Estimated Useful Life Tangible assets acquired $ 2,741 N/A Liabilities assumed (Note 8) (3,627 ) N/A Developed technology 3,800 5 years Customer relationships 2,080 4 years Tradename 260 3 years Goodwill 8,034 Indefinite Total purchase price $ 13,288 The values assigned to the intangible assets are based in part on a third-party valuation analysis, which includes estimates and judgments regarding expectations for success and the life cycle of solutions and technologies acquired.

Restructuring Activities

Restructuring Activities	12 Months Ended
	Dec. 31, 2017
Restructuring And Related Activities [Abstract]
Restructuring Activities	4. Restructuring Activities 2016 Restructuring Plan During 2016, the Company executed an organizational restructuring (the “2016 Restructuring Plan”) primarily to improve cost efficiencies and effectiveness in sales. The Company recorded $596 of restructuring related expenses in connection with the 2016 Restructuring Plan for the year ended December 31, 2016. Actions pursuant to the 2016 Restructuring Plan were complete as of December 31, 2016, and there were no associated costs during the year ended December 31, 2017 2015 Restructuring Plan During 2015, the Company executed organizational restructurings (the “2015 Restructuring Plans”) primarily to improve cost efficiencies and realign its sales, customer success and marketing operations. The Company recorded $1,214 of restructuring related expenses in connection with the 2015 Restructuring Plans for the year ended December 31, 2015. Actions pursuant to the 2015 Restructuring Plans were complete as of December 31, 2015, and there were no associated costs during the years ended December 31, 2017 and 2016 .

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Balance Sheet Components	5. Balance Sheet Components The following table shows the components of property and equipment as of the dates presented: December 31, Estimated Useful Life 2017 2016 Computer equipment 3 years $ 29,938 $ 28,905 Software, including internally developed software 3 years 23,389 21,323 Leasehold improvements Shorter of useful life or lease term 4,617 4,613 Office equipment, furniture and fixtures 3 to 5 years 2,127 2,284 60,071 57,125 Less: Accumulated depreciation and amortization (44,512 ) (36,544 ) $ 15,559 $ 20,581 Depreciation and amortization of internally developed software for 2017, 2016 and 2015 was $8,427, $9,023, and $9,543, respectively. The following table shows the components of accrued expenses and other current liabilities as of the dates presented: December 31, 2017 2016 Accrued salary and payroll-related expenses $ 4,372 $ 3,894 Accrued accounts payable 2,161 1,915 Customer advances 2,003 1,582 Deferred rent 475 408 Sales and use tax payable 341 210 Income taxes payable 142 — Other 521 353 $ 10,015 $ 8,362

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	6. Goodwill and Intangible Assets The goodwill balance as of December 31, 2017 of $16,768 was the result of prior business acquisitions, including as disclosed in Note 3 of these consolidated financial statements. Due to a continued stock price decline, the Company’s market capitalization decreased to a value below the net book value of the Company’s net assets during the second quarter of 2017, triggering the Company to perform an interim goodwill impairment test at that time. Effective April 1, 2017, the Company early adopted ASU 2017-04, Intangibles – Goodwill and Other: Simplifying the Accounting for Goodwill Impairment For the purposes of the goodwill impairment test performed during the three months ended June 30, 2017, the Company estimated the fair value of its sole reporting unit using the market approach. Under the market approach, the Company utilized the market capitalization of its fully diluted common stock, and applied an estimated control premium based on an analysis of control premiums paid in acquisitions of companies in the same or similar industries as the Company. Because the significant inputs used in this analysis are readily available from public markets or can be derived from observable market transactions, they have been classified as level 2 within the fair value hierarchy (Note 7). Based on this approach, the Company determined that the carrying value of its sole reporting unit exceeded its fair value by $2,797, which has been recorded as an impairment of goodwill in the consolidated financial statements for the year ended December 31, 2017. No goodwill triggering events were identified during the six months ended December 31, 2017, including the Company’s annual goodwill impairment test in the fourth quarter. The activity for the year ended December 31, 2017 consisted of the following: Balance at December 31, 2016 $ 19,318 Impairment (2,797 ) Foreign currency translation adjustments 247 Balance at December 31, 2017 $ 16,768 Intangible assets consisted of the following as of the dates presented (in thousands except years): December 31, 2017 December 31, 2016 Estimated Useful Life Developed technology $ 9,910 $ 9,910 5 to 6 years Customer relationships 3,370 3,370 4 years Non-compete agreements and tradenames 1,390 1,390 2 to 3 years 14,670 14,670 Less: accumulated amortization (10,195 ) (7,345 ) $ 4,475 $ 7,325 Amortization expense for 2017, 2016 and 2015 was $2,850, $3,080, and $3,134. Future estimated amortization of intangible assets as of December 31, 2017 is presented below: Year ending December 31, 2018 $ 2,537 Year ending December 31, 2019 1,843 Year ending December 31, 2020 95 $ 4,475

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	7. Fair Value Measurements Account balances measured at fair value on a recurring basis include the following as of the dates presented: December 31, 2017 2016 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Cash equivalents Money market funds $ 8,831 $ — $ — $ 15,657 $ — $ — The Company’s cash equivalents as of December 31, 2017 and 2016 consisted of money market funds that are classified as level 1. The fair value of the Company’s money market funds approximated amortized cost and, as such, there were no unrealized gains or losses on money market funds as of December 31, 2017 and 2016. As of December 31, 2017 and 2016, amounts of $18,713 and $18,763, respectively, were held in bank deposits.

Debt

Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Debt	8. Debt Revolving Credit Facility In July 2015, the Company entered into an amendment to an existing revolving credit facility (“Revolving Credit Facility”) agreement with Silicon Valley Bank to increase the related borrowing limits up to the lesser of $20,000 or 80% of the Company’s eligible accounts receivable. Also, the expiration date of the Revolving Credit Facility was extended to July 31, 2017, and the annual interest rate was amended to (a) the prime rate or (b) the London interbank offered rate then in effect, plus a margin of 2.75%, payable on a monthly basis. The amendment contained affirmative and negative covenants, including covenants related to the delivery of financial and other information, the maintenance of certain financial covenants, as well as limitations on dispositions, changes in business or management, mergers or consolidations, dividends and other corporate actions. In December 2016, the Company terminated the Revolving Credit Facility prior to its expiration. No amounts were outstanding pursuant to the Revolving Credit Facility at the date of termination. Capital Lease Arrangements At various dates between August 2015 and September 2017, the Company entered into nine separate capital lease arrangements with an equipment manufacturer to finance the acquisition of additional computer equipment. These leases have effective annual interest rates between 5.7% and 7.9% and are repayable in 36 to 48 consecutive equal monthly installments of principal and interest. At the end of the lease periods for these capital lease arrangements, the Company has the option to purchase the underlying equipment at the estimated fair market value or for a nominal amount. In September and October 2016, the Company entered into two capital lease arrangements with a different equipment manufacturer to finance the acquisition of additional computer equipment. These leases have an effective annual interest rate of 5.2% and are repayable in 48 consecutive equal monthly installments of principal and interest. At the end of the lease periods of both leases, the Company has the option to purchase or renew the lease for the underlying equipment at the estimated fair market value. As of December 31, 2017 and 2016, the net book value of the computer equipment under all capital leases was $2,861 and $3,158, respectively, and the remaining principal balance payable was $3,103 and $3,411, respectively. The capital leases are collateralized by the underlying computer equipment. The maturities of capital lease obligations as of December 31, 2017 are as follows: Year Ending December 31, 2018 $ 1,416 December 31, 2019 1,137 December 31, 2020 538 December 31, 2021 12 3,103 Less: Current portion (1,416 ) Capital lease obligations, non-current $ 1,687 In connection with the acquisition of SocialMoov in February 2015 (Note 3), the Company assumed outstanding debt totaling approximately $1,043, which consisted primarily of individual loans payable to (a) an agency of the French government, (b) a French public-sector investment bank and (c) a French private-sector financial institution. These loans were fully repaid during the year ended December 31, 2015. In December 2014, the Company entered into a standby letter of credit agreement for $1,293 with Silicon Valley Bank in connection with the non-cancelable lease for the Company’s corporate headquarters in San Francisco. Following the termination of the Revolving Credit Facility in December 2016, the Company was required to separately restrict from use $1,293 in cash held at Silicon Valley Bank to secure this letter of credit. This balance has been classified as restricted cash on the consolidated balance sheets.

Common Stock

Common Stock	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Common Stock	9. Common Stock As of December 31, 2017 and 2016, the Company’s amended certificate of incorporation authorizes the issuance of 142,857 shares of $0.001 par value common stock, and 10,000 shares of $0.001 par value convertible preferred stock. Reserved shares of common stock are as follows for the dates presented: December 31, 2017 2016 Options or RSUs available for future grant under stock option plans 999 839 Options outstanding under stock option plans 436 536 RSUs outstanding under stock option plans 568 429 Shares available for future issuance under employee stock purchase plan 182 170 Shares to be issued in connection with acquisition of SocialMoov — 66 2,185 2,040

Equity Award Plans

Equity Award Plans	12 Months Ended
	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity Award Plans	10. Equity Award Plans In April 2006, the Company’s Board of Directors (the “Board”) adopted and the stockholders approved the 2006 Stock Option Plan (“2006 Plan”). The 2006 Plan provides for the grant of incentive stock options under the federal tax laws and non-statutory stock options. Only employees may receive incentive stock options, but non-statutory stock options may be granted to employees, non-employee directors and consultants. The stock options are exercisable at a price equal to the market value of the underlying shares of common stock on the date of the grant as determined by the Board. The term of options granted under the 2006 Plan may not exceed Certain options are eligible for exercise prior to vesting. Exercised but unvested shares of common stock are subject to repurchase by the Company at the initial exercise price. The proceeds from the shares of common stock subject to repurchase are classified as a liability and reclassified to equity as the shares vest In February 2013, the Board and stockholders approved the 2013 Equity Incentive Plan (“2013 Plan”), under which 643 shares of common stock were originally reserved for issuance. Additionally, all reserved and unissued shares under the 2006 Plan at the time the 2013 Plan became effective were eligible for issuance under the 2013 Plan. The 2013 Plan became effective on March 21, 2013, at which time the Company ceased to grant equity awards under the 2006 Plan. The 2013 Plan authorizes the award of stock options, restricted stock awards, stock appreciation rights, RSUs, performance awards and stock bonuses to the Company’s employees, directors, consultants, independent contractors and advisors. On January 1 of each of the first 10 calendar years through 2023, the number of shares of common stock reserved under the 2013 Equity Incentive Plan will automatically increase by an amount equal to 5% of the total outstanding shares as of immediately preceding December 31, or such lesser number of shares as determined by the Board. Pursuant to the terms of the 2013 Plan, the shares available for issuance increased by approximately 286 shares of common stock on January 1, 2018. Stock Options Under the 2006 Plan and the 2013 Plan, the term of options granted may not exceed ten years. Unless the terms of an optionee’s stock option agreement provide otherwise, if an optionee’s service relationship with the Company, or any of its affiliates, ceases for any reason other than disability or death, the optionee may exercise the vested portion of any options for three months after the date of such termination. If an optionee’s service relationship with the Company, or any of its affiliates, ceases due to disability or death (or an optionee dies within a certain period following cessation of service), the optionee or a beneficiary may exercise any vested options for a period of 12 months. In no event, however, may an option be exercised beyond the expiration of its term. A summary of activity under the 2006 Plan and the 2013 Plan is as follows (in thousands, except per share amounts and years): Options Outstanding Number of Shares Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term (in Years) Aggregate Intrinsic Value Balance at December 31, 2014 911 $ 55.93 7.82 $ 9,697 Options granted 329 40.95 7.70 Options exercised (104 ) 13.86 — Options forfeited and cancelled (285 ) 62.44 — Balance at December 31, 2015 851 $ 53.06 7.85 $ 957 Options granted 172 18.62 6.82 Options exercised (38 ) 10.36 — Options forfeited and cancelled (449 ) 54.53 — Balance at December 31, 2016 536 $ 43.83 7.48 $ 194 Options granted 79 11.66 9.35 Options forfeited and cancelled (179 ) 44.82 — Balance at December 31, 2017 436 $ 37.60 7.04 $ 65 Options exercisable as of December 31, 2017 303 $ 45.97 6.25 $ 43 Options vested as of December 31, 2017 302 $ 45.96 6.25 $ 43 Options vested and expected to vest as of December 31, 2017 427 $ 37.96 7.01 $ 64 The intrinsic value of options exercised during 2016 and 2015 was $328 and $2,935, respectively. The total estimated fair value of options vested during 2017, 2016 and 2015 was $1,451, $5,424, and $7,573, respectively. RSUs A summary of RSUs granted and unvested under the 2013 Plan during 2017 and 2016 is as follows (in thousands, except per unit amounts): RSUs Outstanding Number of Shares Weighted Average Grant Date Fair Value Per Unit Granted and unvested at December 31, 2014 110 $ 65.52 RSUs granted 169 39.76 RSUs vested (20 ) 68.81 RSUs cancelled (84 ) 54.53 Granted and unvested at December 31, 2015 175 $ 65.52 RSUs granted 446 18.76 RSUs vested (30 ) 50.33 RSUs cancelled and withheld to cover taxes (162 ) 30.80 Granted and unvested at December 31, 2016 429 $ 21.48 RSUs granted 405 10.56 RSUs vested, net (78 ) 21.29 RSUs cancelled and withheld to cover taxes (188 ) 19.97 Granted and unvested at December 31, 2017 568 $ 14.22 Employee Stock Purchase Plan In February 2013, the Board and stockholders approved the 2013 Employee Stock Purchase Plan (“2013 ESPP”), under which 143 shares of common stock were originally reserved for issuance. The 2013 ESPP became effective on March 22, 2013. The 2013 ESPP provides generally for six-month purchase periods and the purchase price for shares of common stock purchased under the 2013 ESPP will be 85% of the lesser of the fair market value of the common stock on (1) the first trading day of the applicable offering period and (2) the last trading day of each purchase period in the applicable offering period. On January 1 of each of the first 10 calendar years following the first offering date, the number of shares reserved under the 2013 ESPP will automatically increase by an amount equal to 1% of the total outstanding shares as of the immediately preceding December 31, but not to exceed 100 shares. Pursuant to the terms of the 2013 ESPP, the shares available for issuance increased by approximately 57 shares on January 1, 2018. During 2017 and 2016, 43 and 42 shares, respectively, were issued under the 2013 ESPP.

Stock-Based Compensation Expens

Stock-Based Compensation Expense	12 Months Ended
	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation Expense	11. Stock-Based Compensation Expense For stock-based awards granted by the Company, stock-based compensation expense is measured at grant date based on the fair value of the award and is expensed over the requisite service period. The Company recorded stock-based compensation expense of $4,704, $10,295 and $15,619 for 2017, 2016 and 2015, respectively. Stock Options The Company uses the Black-Scholes option-pricing model to estimate the fair value of options. This model requires the input of highly subjective assumptions including the expected volatility, risk-free interest rate, and the expected life of options. The Company used the following assumptions: Years Ended December 31, 2017 2016 2015 Dividend yield — — — Expected volatility 47.3 % 47.5 % 49.1 % Risk-free interest rate 2.03 % 1.38 % 1.75 % Expected life of options (in years) 6.25 6.25 6.25 Weighted-average grant-date fair value $ 5.61 $ 8.82 $ 20.16 Weighted-average grant-date exercise price $ 11.66 $ 18.62 $ 40.95 As the Company has limited historical option exercise data, the expected term of the stock options granted to employees was calculated based on the simplified method. Under the simplified method, the expected term is equal to the average of an option’s weighted-average vesting period and its contractual term. Pursuant to the Securities and Exchange Commission (“SEC”) Staff Accounting Bulletin (“SAB”) No. 110, the Company is permitted to continue using the simplified method until sufficient information regarding exercise behavior, such as historical exercise data or exercise information from external sources, becomes available. The Company estimates the expected volatility of its common stock on the date of grant based on the historical stock volatilities of similar publicly-traded entities over a period equal to the expected terms of the options, as the Company does not have sufficient trading history to use the volatility of its own common stock. The Company has no history or expectation of paying cash dividends on its common stock. The risk-free interest rate is based on the United States Treasury yield for a term consistent with the expected life of the options in effect at the time of grant. The Company recognized stock-based compensation expense only for those shares expected to vest over the requisite service period of the underlying award. The company determines its estimated forfeiture rated based on an analysis of its actual forfeitures and will continue to evaluate the appropriateness of the forfeiture rate based on recent forfeiture activity and expected future employee turnover, if any. Changes in the estimated forfeiture rate can have a significant effect on reported stock-based compensation expense, as the cumulative effect of adjusting the rate for all expense is recognized in the period the forfeiture estimate is changed. No compensation cost is recorded for stock options that do not vest, and the compensation cost for vested stock options, whether forfeited or not, is not reversed. Cash proceeds from the exercise of stock options were zero, $390, and $1,439 during 2017, 2016 and 2015, respectively. Compensation expense is recognized ratably over the requisite service period. As of December 31, 2017 and 2016, there was $934 and $2,706, respectively, of unrecognized compensation cost, adjusted for estimated forfeitures, related to options, which is expected to be recognized over a weighted-average period of 1.6 and 2.1 years, respectively. Restricted Stock and RSUs As of December 31, 2017 and 2016, there was $6,428 and $7,973, respectively, of unrecognized compensation cost, adjusted for estimated forfeitures, related to restricted stock and RSUs, which is expected to be recognized over a weighted-average period of 2.1 and 2.3 years, respectively. The Company uses the fair market value of the underlying common stock on the dates of grant to determine the fair value of restricted stock and RSUs. Stock-based compensation expense related to these awards is recognized on a straight-line basis over the service period of the award for the estimated number of shares that are ultimately expected to vest. Employee Stock Purchase Plan The Company estimates the fair value of purchase rights under the 2013 ESPP using the Black-Scholes valuation model. The fair value of each purchase right under the 2013 ESPP was estimated on the date of grant using the Black-Scholes option valuation model and the straight-line attribution approach with assumptions substantially similar to those used for the valuation of stock option awards.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes The components of the Company’s loss before provision for income taxes were as follows: Years Ended December 31, 2017 2016 2015 United States of America $ (15,740 ) $ (7,595 ) $ (17,173 ) International (14,744 ) (7,481 ) (15,171 ) $ (30,484 ) $ (15,076 ) $ (32,344 ) The components of the provision for income taxes were as follows: Years Ended December 31, 2017 2016 2015 Current income tax provision Federal $ — $ — $ — State 64 58 111 Foreign 1,301 1,708 1,193 Total current income tax provision 1,365 1,766 1,304 Deferred income tax benefit Federal — — - State — — - Foreign (358 ) (362 ) (299 ) Total deferred income tax benefit (358 ) (362 ) (299 ) Provision for income taxes $ 1,007 $ 1,404 $ 1,005 The differences in the total provision for income taxes that would result from applying the 34% federal statutory rate to loss before provision for income taxes and the reported provision for income taxes were as follows: Years Ended December 31, 2017 2016 2015 Tax benefit at U.S. statutory rate $ (10,365 ) $ (5,126 ) $ (10,997 ) State income taxes, net of federal benefit (2,858 ) (147 ) (104 ) Foreign income and withholding taxes 5,578 4,317 6,033 Impact of change to U.S. statutory rate from Tax Cuts and Jobs Act 14,302 — — Stock-based compensation 1,085 2,231 1,039 Change in valuation allowance (8,158 ) 155 3,807 Research and development credits (382 ) (736 ) (1,067 ) Uncertain tax positions 1,995 1,146 1,277 Provision to return adjustments 153 (484 ) 848 Impact of adoption of ASU 2016-09 (1,291 ) — — Other 948 48 169 $ 1,007 $ 1,404 $ 1,005 Major components of the Company’s deferred tax assets (liabilities) as of December 31, 2017 and 2016 are as follows: December 31, 2017 2016 Net operating loss $ 25,002 $ 32,551 Accruals and reserves 1,656 2,934 Research and development credits 8,757 7,368 Stock-based compensation 2,796 4,622 Property and equipment and intangible assets (710 ) (1,855 ) Other 3,161 2,842 Net deferred tax assets 40,662 48,462 Valuation allowance (41,224 ) (49,382 ) Total non-current net deferred tax liabilities, net of valuation allowance $ (562 ) $ (920 ) The Tax Reform Act of 1986, as amended, imposes restrictions on the utilization of net operating losses and tax credit carryforwards in certain situations where changes occur in the stock ownership of a corporation. Utilization of a domestic net operation loss or tax credit carryforward may be subject to a substantial limitation due to ownership changes that may have occurred or that could occur in the future, as required by Internal Revenue Code Section 382 (“IRC Section 382”), as well as similar state provisions. Accordingly, a company’s ability to use net operating losses may be limited as prescribed under IRC Section 382. Events which may cause limitations in the amount of the net operating losses that the Company may use in any one year include, but are not limited to, a cumulative ownership change of more than 50% over a three-year period. The Company assessed the application of IRC Section 382 during the fourth quarter of 2017 and concluded that no such limitation currently applies. This conclusion will be monitored in the future as circumstances dictate. In the event the Company experiences any subsequent changes in ownership, the amount of net operating losses and research and development credit carryovers available in any taxable year could be limited and may expire unutilized. As of December 31, 2017, the Company had federal and state net operating loss carryforwards of approximately $110,087 and $91,585, respectively. The federal net operating loss carryforward will begin expiring in 2026 and the state net operating loss carryforward will begin expiring in 2022. As of December 31, 2017, the Company had federal and state research and development credits of approximately $6,139 and $6,451, respectively. The federal research and development credits will begin expiring in 2026. The state research and development credits are not currently subject to expiration. The Company has recorded a full valuation allowance against its otherwise recognizable deferred income tax assets as of December 31, 2017 and 2016 (except for the deferred income tax assets associated with certain of the Company’s foreign subsidiaries). The Company has determined, after evaluating all positive and negative historical and prospective evidence, that it is more likely than not that the deferred tax assets will not be realized. The valuation allowance decreased by $8,158 during the year ended December 31, 2017, and increased by $469 and $5,467 during the years ended December 31, 2016 and 2015, respectively. The Company files federal, state and foreign income tax returns in jurisdictions with varying statutes of limitations. In the normal course of business, the Company is subject to examination by taxing authorities throughout the world. These audits include questioning the timing and amount of deduction, the nexus of income among various tax jurisdictions and compliance with state, local and foreign tax laws. The Company is not currently under any examination by any federal or state tax authorities, but is currently under audit by the French Tax Authority for the tax years of 2012 through 2016. Because of net operating loss and credit carry forwards, all of the Company’s tax years dating to inception in 2006 remain open to examination. Uncertain Tax Positions As of December 31, 2017 and 2016, the Company had uncertain tax positions of $1,610 and $1,049, respectively, that if recognized would impact the annual effective tax rate. During 2017, 2016 and 2015, the Company did not recognize any interest or penalties related to uncertain tax positions. The aggregate changes in the balance of gross uncertain tax positions were as follows: Ending balance as of December 31, 2014 $ 1,581 Increase in balances related to tax positions taken during the current period 3,196 Increase in balances related to tax positions taken during the prior period 2,781 Ending balance as of December 31, 2015 7,558 Decrease in balances related to tax positions taken during the current period (2 ) Increase in balances related to tax positions taken during the prior period 1,240 Ending balance as of December 31, 2016 8,796 Increase in balances related to tax positions taken during the current period 1,738 Decrease in balances related to tax positions taken during the prior period (9 ) Decrease in balances due to change in United States statutory rate (2,101 ) Ending balance as of December 31, 2017 $ 8,424 The Company does not anticipate that the amount of uncertain tax positions relating to tax positions existing at December 31, 2017 will materially increase or decrease within the next twelve months. The Tax Cuts and Jobs Act On December 22, 2017, the United States enacted the Tax Cuts and Jobs Act (“TCJA”), which instituted fundamental changes to the taxation of multinational corporations, including a reduction the U.S. corporate income tax rate to 21% beginning in 2018. As a result, the Company re-measured its deferred tax assets and deferred tax liabilities at the new lower corporate income tax rate and reduced them by $18,696 and $4,394, respectively, with a corresponding net adjustment to the valuation allowance of $14,302 for the year ended December 31, 2017. The TCJA also requires a one-time transition tax on the mandatory deemed repatriation of the cumulative earnings of certain of the Company’s foreign subsidiaries as of December 31, 2017. To determine the amount of this transition tax, the Company must determine the amount of earnings generated since inception by the relevant foreign subsidiaries, as well as the amount of non-U.S. income taxes paid on such earnings, in addition to potentially other factors. The Company believes that no such tax will be due, as its foreign subsidiaries have accumulated significant losses. In addition, the TCJA imposes a U.S. tax on global intangible low-taxed income (“GILTI”) that is earned by certain foreign subsidiaries. Because of the complexity of the new GILTI tax rules, the Company’s management is continuing to evaluate the provision of the TCJA and its application on the accounting for income taxes. In accordance with GAAP, the Company is allowed to make an accounting policy choice of either (1) treating taxes related to GILTI as a current period expense when incurred, or (2) factoring such amounts into the measurement of deferred taxes. Because the assessment of the impact of GILTI depends not only on the Company’s current structure, but also its intent and ability to modify its structure and business, the Company is not yet able to reasonably estimate the effect of this provision of the TCJA. Therefore, the Company has not made any adjustment related to potential GILTI tax in the consolidated financial statements, and has not made a policy decision regarding whether to record deferred taxes related to GILTI. The base-erosion and anti-abuse tax (“BEAT”) provisions in the TCJA eliminates the deduction of certain base-erosion payments made to related foreign corporations, and impose a minimum tax if greater than regular tax. The Company does not expect it will be subject to this tax and therefore has not included any tax impacts of BEAT in its consolidated financial statements for the year ended December 31, 2017. On December 22, 2017, the SEC staff issued Staff Accounting Bulletin No. 118 (“SAB 118”) to address the application of GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the TCJA. The Company has recognized the provisional tax impacts related to the revaluation of deferred tax assets and liabilities and included these amounts in its consolidated financial statements for the year ended December 31, 2017. The ultimate impact may materially differ from these provisional amounts due to, among other things, additional analysis, changes in interpretations and assumptions the Company has made, additional regulatory guidance that may be issued, and actions the Company may take as a result of the TCJA. The accounting is expected to be completed when the 2017 U.S. corporate income tax return is filed in 2018.

Net Loss Per Share Available to

Net Loss Per Share Available to Common Stockholders	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Net Loss Per Share Available to Common Stockholders	13. Net Loss Per Share Available to Common Stockholders Basic net loss per share available to common stockholders is calculated by dividing the net loss available to common stockholders by the weighted-average number of shares of common stock outstanding for the period. The weighted-average number of shares of common stock used to calculate the Company’s basic net loss per share available to common stockholders excludes those shares subject to repurchase related to unvested common shares, stock options that were exercised prior to vesting, restricted stock issued and RSUs settled for shares of common stock, as these shares are not deemed to be outstanding for accounting purposes until they vest. The diluted net loss per share of common stock is computed by dividing the net loss using the weighted-average number of shares of common stock, excluding common stock subject to repurchase, and, if dilutive, potential shares of common stock outstanding during the period. Potential shares of common stock consist of common stock subject to repurchase, stock options to purchase common stock, restricted common stock issued and RSUs settled for shares of common stock. The following table presents the calculation of basic and diluted net loss per share for the periods presented (in thousands except per share amounts): Years Ended December 31, 2017 2016 2015 Numerator: Net loss available to common stockholders $ (31,491 ) $ (16,480 ) $ (33,349 ) Denominator: Weighted average number of shares, basic and diluted 5,638 5,474 5,225 Net loss per share available to common stockholders: Basic and diluted net loss per common share available to common stockholders $ (5.59 ) $ (3.01 ) $ (6.38 ) The following table presents the potential common shares outstanding that were excluded from the computation of diluted net loss per share available to common stockholders for the periods presented because including them would have been anti-dilutive: Years Ended December 31, 2017 2016 2015 Options to purchase common stock 436 536 851 RSUs 568 429 175 Restricted common stock — — 19 Common stock subject to repurchase — 1 3 1,004 966 1,048

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment Reporting	14. Segment Reporting The Company defines the term “chief operating decision maker” to be the Chief Executive Officer. The Chief Executive Officer reviews the financial information presented on a consolidated basis for purposes of allocating resources and evaluation of financial performance. Accordingly, the Company has determined that it operates as a single reportable and operating segment. Revenues by geographic area, based on the billing location of the customer, were as follows: Years Ended December 31, 2017 2016 2015 United States of America $ 49,637 $ 69,220 $ 72,942 International 25,354 30,658 35,588 Total revenues, net $ 74,991 $ 99,878 $ 108,530 Long-lived assets, excluding goodwill and intangible assets, by geographic area were as follows: December 31, 2017 2016 United States of America $ 15,069 $ 19,861 International 490 720 Total long-lived assets, net $ 15,559 $ 20,581

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	15. Commitments and Contingencies Operating Leases Rent expense for 2017, 2016 and 2015 was $8,519, $8,760, and $8,673, respectively. The Company has leased office space in San Francisco, Austin, Chicago, Dublin, Hamburg, London, New York, Paris, Portland, Sydney, Shanghai and Tokyo under non-cancelable operating leases, which expire between 2018 and 2024. Additionally, the Company subleases portions of its San Francisco and Portland office spaces, and leases the space utilized for data center operations. Future minimum lease payments for significant operating leases, net of sublease payments, as of December 31, 2017 were as follows: Year Ending December 31, 2018 $ 7,439 December 31, 2019 7,986 December 31, 2020 3,664 December 31, 2021 3,444 December 31, 2022 2,211 Thereafter 475 $ 25,219 Legal Matters From time to time, the Company may be involved in lawsuits, claims, investigations and proceedings, consisting of intellectual property, commercial, employment and other matters, which arise in the ordinary course of business. In accordance with GAAP, the Company records a liability when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. These provisions are reviewed at least quarterly and adjusted to reflect the impact of negotiations, settlements, ruling, advice of legal counsel and other information and events pertaining to a particular case. Litigation is inherently unpredictable. If any unfavorable ruling were to occur in any specific period or if a loss becomes probable and estimable, there exists the possibility of a material adverse impact on the Company’s results of operations, financial position or cash flows. Indemnification The Company enters into standard indemnification agreements in the ordinary course of business. Pursuant to the agreements, each party may indemnify, defend and hold the other party harmless with respect to such claim, suit or proceeding brought against it by a third party alleging that the indemnifying party’s intellectual property infringes upon the intellectual property of the third party, or results from a breach of the indemnifying party’s representations and warranties or covenants, or that results from any acts of negligence or willful misconduct. The term of these indemnification agreements is generally perpetual any time after execution of the agreement. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is unlimited. Historically, the Company has not been obligated to make significant payments for these obligations and no liabilities have been recorded for these obligations on the consolidated balance sheets as of December 31, 2017 and 2016. The Company also indemnifies its officers and directors for certain events or occurrences, subject to certain limits, while the officer or director is or was serving at the Company’s request in such capacity. The maximum amount of potential future indemnification is unlimited; however, the Company has a Directors and Officers insurance policy that limits its exposure and enables the Company to recover a portion of any future amounts paid. Historically, the Company has not been obligated to make any payments for these obligations and no liabilities have been recorded for these obligations on the consolidated balance sheets as of December 31, 2017 and 2016. Other Contingencies The Company is subject to claims and assessments from time to time in the ordinary course of business. The Company’s management does not believe that any such matters, individually or in the aggregate, will have a material adverse effect on the Company’s financial position, results of operations or cash flows.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2017
Postemployment Benefits [Abstract]
Employee Benefit Plans	16. Employee Benefit Plans The Company sponsors a 401(k) defined contribution plan covering all employees in the United States. The Board determines contributions made by the Company annually. The Company made no contributions under this plan for 2017, 2016 and 2015. The Company also sponsors a statutorily required defined contribution pension plan covering all employees in the United Kingdom. The Company made contributions to this plan of $75, $85 and $93 during the years ended December 31, 2017, 2016 and 2015, respectively.

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Event	17. Subsequent Event In January 2018, the Company initiated a restructuring plan designed to reduce operating expenses in response to declines in revenues and to better align the Company’s efforts to return to growth. The Company estimates that it will incur pre-tax charges and costs of approximately $1,000 to $1,500 due to this restructuring, primarily related to severance, other one-time termination benefits and reductions in office space. These costs are primarily expected to be incurred during the first quarter of 2018, and the Company expects the majority of activities related to this restructuring to be completed by the first half of 2018.

Summary of Significant Accoun24

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Liquidity	Liquidity The Company has incurred significant losses in each fiscal year since its incorporation in 2006 and management expects such losses to continue over the next several years. The Company experienced net losses of $31,491, $16,480 and $33,349 during 2017, 2016 and 2015, respectively. As of December 31, 2017, the Company had an accumulated deficit of $227,704. The Company had cash, cash equivalents and restricted cash of $28,837 as of December 31, 2017. Management expects to incur additional losses and experience negative cash flows in the future. To continue to fund operations, including research and development, the Company will need to increase revenues, lower costs and/or raise additional capital. The Company believes that its cash, cash equivalents and restricted cash will provide sufficient funds for the Company to continue as a going concern for at least 12 months from the date of issuance of these consolidated financial statements.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated upon consolidation.
Reclassifications	Reclassifications When necessary, reclassifications have been made to prior period financial information to conform to the current year presentation.
Reverse Stock Split and Reduction in Authorized Shares	Reverse Stock Split and Reduction in Authorized Shares On October 5, 2017, the Company effected a reverse stock split of its outstanding common stock. As a result of the reverse stock split, each seven outstanding shares of the Company’s common stock were combined into one outstanding share of common stock, without any change in par value. The common stock began trading on the New York Stock Exchange on a split-adjusted basis on October 6, 2017. No fractional shares were issued in connection with the reverse stock split and the Company paid in cash the fair value of such fractional shares. On October 5, 2017, the Company also effected a reduction in the Company’s authorized shares of common stock, from 500,000 shares to 142,857 shares. There was no change to the number of authorized shares of convertible preferred stock, which remained at 10,000 shares. All share and per share amounts of the Company’s common stock, as well as stock options and restricted stock units (“RSUs”), included in the accompanying consolidated financial statements have been adjusted to give effect to the reverse stock split for all periods presented. In addition, as a result of the reverse stock split, the Company reclassified an amount equal to the reduction in common stock at par value to additional paid-in capital on its consolidated balance sheets.
Accounting Estimates	Accounting Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States (“GAAP”) requires management to make certain estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company is subject to uncertainties such as the impact of future events, economic and political factors and changes in the Company’s business environment; therefore, actual results could differ from these estimates. Accordingly, the accounting estimates used in the preparation of the Company’s financial statements will change as new events occur, as more experience is acquired, as additional information is obtained and as the Company’s operating environment changes. Changes in estimates are made when circumstances warrant. Such changes in estimates and refinements in estimation methodologies are reflected in reported results of operations and if material, the effects of changes in estimates are disclosed in the notes to the consolidated financial statements. Significant estimates and assumptions by management affect the allowances for doubtful accounts and customer credits, the carrying value of long-lived assets (including goodwill and intangible assets), the useful lives of long-lived assets, the accounting for income taxes, and stock-based compensation.
Certain Significant Risks and Uncertainties	Certain Significant Risks and Uncertainties The Company operates in a rapidly changing environment that involves a number of risks, some of which are beyond the Company’s control that could have a material adverse effect on the Company’s business, operating results, and financial condition. These risks include, among others, the Company’s history of losses and negative cash flows; the highly competitive environment in which the Company operates; the ability to maintain and increase usage rate of the Company’s platform and the ability for the Company to increase demand for its solutions.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist of cash, cash equivalents and accounts receivable. The Company’s cash and cash equivalents are placed with high-credit-quality financial institutions and issuers, and at times exceed federally insured limits. The Company has not experienced any loss relating to cash and cash equivalents in these accounts. The Company performs periodic credit evaluations of its customers and generally does not require collateral. As of December 31, 2017 and 2016, no single customer accounted for 10% or more of net accounts receivable. No single customer accounted for 10% or more of consolidated revenues, net during the years ended December 31, 2017, 2016 and 2015.
Cash and Cash Equivalents and Restricted Cash	Cash and Cash Equivalents and Restricted Cash The Company considers all highly liquid investments with an original or remaining maturity from the Company’s date of purchase of 90 days or less to be cash equivalents. Deposits held with financial institutions are likely to exceed the amount of insurance on these deposits. Cash equivalents consist of money market funds, which are readily convertible into cash and have original maturity dates of less than three months from the date of their respective purchases. Cash equivalents were $8,831 and $15,657 as of December 31, 2017 and 2016, respectively. Restricted cash consists of deposits held with a financial institution to secure the Company’s non-cancelable lease for its corporate headquarters in San Francisco (see Note 8).
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company’s financial instruments, including accounts receivable, accounts payable and accrued expenses are carried at cost, which approximates fair value because of the short-term nature of those instruments. Based on borrowing rates available to the Company for loans with similar terms and maturities, and in consideration of the Company’s credit risk profile, the carrying value of outstanding capital lease obligations (Note 8) approximates fair value (level 2 within the fair value hierarchy). The Company measures and reports certain financial assets at fair value on a recurring basis, including its investments in money market funds. The fair value hierarchy prioritizes the inputs into three broad levels: Level 1 Inputs are unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 Inputs are quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument. Level 3 Inputs are unobservable inputs based on the Company’s assumptions. A financial instrument’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement.
Allowance for Doubtful Accounts and Revenue Credits	Allowance for Doubtful Accounts and Revenue Credits The allowance for doubtful accounts reflects the Company’s best estimate of probable losses inherent in the Company’s receivables portfolio determined on the basis of historical experience, specific allowances for known troubled accounts and other currently available evidence. The Company has not experienced significant credit losses from its accounts receivable. The Company performs a regular review of its customers’ payment histories and associated credit risks and it does not require collateral from its customers. Certain contracts with advertising agencies contain sequential liability provisions, whereby the agency does not have an obligation to pay the Company until payment is received from the agency’s customers. In these circumstances, the Company evaluates the credit worthiness of the agency’s customers, in addition to the agency itself. The following are changes in the allowance for doubtful accounts during 2017, 2016 and 2015, respectively. Years Ended December 31, 2017 2016 2015 Balances at beginning of year $ 3,510 $ 2,188 $ 989 Additions to expense 1,507 2,328 1,210 Additions against goodwill — — 442 Write-offs and other deductions (989 ) (1,006 ) (453 ) Balances at end of year $ 4,028 $ 3,510 $ 2,188 From time to time, the Company provides credits to customers and an allowance is made based on historical credit activity. As of December 31, 2017 and 2016, the Company recorded an allowance for potential customer credits in the amount of $799 and $1,947, respectively.
Property and Equipment	Property and Equipment Property and equipment are stated at historical cost less accumulated depreciation and amortization. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the related assets. Upon retirement or sale, the cost and related accumulated depreciation are removed from the balance sheet and the resulting gain or loss is reflected in operations. Major additions and improvements are capitalized while repairs and maintenance that do not extend the life of the asset are charged to operations as incurred. Depreciation and amortization expense is allocated to both cost of revenues and operating expenses.
Internally Developed Software	Internally Developed Software Costs incurred in the development phase are capitalized and amortized over the product’s estimated useful life, which is three years. The Company expenses all costs incurred that relate to planning and post implementation phases of development. Capitalized costs related to internally developed software under development are treated as construction in progress until the program, feature or functionality is ready for its intended use, at which time amortization commences. For 2017, 2016 and 2015, the Company capitalized $2,068, $4,712, and $5,568 of costs related to internally developed software, respectively. Amortization of capitalized costs related to internally developed software was $3,669, $2,988, and $2,550 for 2017, 2016 and 2015, respectively. As of December 31, 2017 and 2016, unamortized internally developed software costs totaled $8,617 and $10,218, respectively. Amortization of internally developed software is reflected in cost of revenues. Costs associated with minor enhancements and maintenance are expensed as incurred.
Goodwill, Intangible Assets and Impairment Assessments	Goodwill, Intangible Assets and Impairment Assessments Goodwill represents the excess of the purchase price in a business combination over the fair value of net tangible and intangible assets acquired. Intangible assets that are not considered to have an indefinite useful life are amortized over their useful lives, which range from two to six years. Estimated remaining useful lives of purchased intangible assets are evaluated to assess whether events or changes in circumstances warrant a revision to the remaining periods of amortization. The Company evaluates goodwill for impairment in the fourth quarter of its fiscal year annually, or more frequently if events or changes in circumstances indicate that these assets may be impaired. For the purposes of impairment testing, the Company has determined that it has one reporting unit. The Company performs its goodwill impairment test using the simplified method, whereby the fair value of this reporting unit is compared to its carrying value. If the fair value of the reporting unit exceeds the carrying value of the net assets assigned to that reporting unit, goodwill is not considered impaired. If the carrying value of the net assets assigned to the reporting unit exceeds the fair value of the reporting unit, then goodwill is considered impaired by an amount equal to that difference. In the first half of 2017, the market capitalization of the Company’s common stock sustained a significant decline so that it fell below the book value of the Company’s net assets, triggering management to conduct an interim goodwill impairment test at that time. The outcome of this goodwill impairment test resulted in an impairment of goodwill of $2,797, which was recorded in the consolidated financial statements during the three months ended June 30, 2017. Refer to Note 6 for further details of the Company’s goodwill impairment assessment. In the second half of 2017, the market capitalization of the Company’s common stock rose above the book value of the Company’s net assets. Management considered that, along with other possible factors affecting the assessment of the Company’s reporting unit for the purposes of performing a goodwill impairment assessment, including management assumptions about expected future revenue forecasts and discount rates, changes in the overall economy, trends in the stock price, any estimated control premium and other operating conditions. Ultimately, no goodwill impairment triggering events were identified in any period subsequent to June 30, 2017, including the Company’s annual goodwill impairment test in the fourth quarter. It is reasonably possible that the Company will not be able to achieve its goals of growing revenues and generating positive cash flows by increasing its customer base and reducing customer turnover. If this were the case, it could result in a further decline in the market capitalization of the Company’s common stock and lead to additional goodwill impairment triggering events. If the Company determines that its goodwill is impaired, it would be required to record a non-cash charge that may or may not be material to its consolidated financial statements.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company evaluates long-lived assets, excluding goodwill, for potential impairment whenever adverse events or changes in circumstances or business climate indicate that expected undiscounted future cash flows related to such long-lived assets may not be sufficient to support the net book value of such assets. An impairment loss is recognized only if the carrying value of a long-lived asset or asset group is not recoverable and exceeds its fair value. The carrying value of a long-lived asset or asset group is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. There were no such impairment losses during 2017, 2016 or 2015.
Operating Leases	Operating Leases The Company’s operating lease agreements include provisions for tenant improvement allowances, certain rent holidays and escalations in the base price of the rent payment. The Company defers tenant improvement allowances and amortizes the balance as a reduction to rent expense over the lease term. The Company records rent holidays and rent escalations on a straight-line basis over the lease term. Deferred rent is included in accrued expenses and other current liabilities, as well as other long-term liabilities in the accompanying consolidated balance sheets.
Revenue Recognition	Revenue Recognition The Company generates revenues principally from subscriptions either directly with advertisers or with advertising agencies to its platform for the management of search, social and display advertising. The Company’s subscription agreements are generally one year or longer in length. The Company’s subscription fee under most contracts is variable based on the value of the advertising spend that the Company’s advertisers manage through the Company’s platform and is generally invoiced on a monthly basis. Contracts with direct advertisers and certain contracts with independent advertising agencies also include a minimum monthly fee that is payable over the duration of the contract. The Company’s customers do not have the right to take possession of the software supporting the application service at any time, nor do the arrangements contain general rights of return. The Company commences revenue recognition for both direct advertisers and advertising agencies when all of the following conditions are met: • persuasive evidence of an arrangement exists; • the Company’s platform is made available to the customer; • the fee is fixed or determinable, and; • collection is reasonably assured. The Company recognizes the total minimum fee for both direct advertisers and independent advertising agencies, where applicable, over the duration of the contract, commencing on the date that the Company’s platform is made available to the customer, provided revenues recognized do not exceed amounts that are invoiced and due. The variable fee, which is based on a percentage of the value of the advertising spend managed through the Company’s platform, is recognized once the amount is fixed or determinable, which is generally on a monthly basis concurrent with the issuance of the customer invoice. Signed contracts are used as evidence of an arrangement. The Company assesses collectability based on a number of factors such as past collection history with the customer and creditworthiness of the customer. Certain agreements with advertising agencies also contain sequential liability provisions, which provide that the agency has no obligation to pay the Company until the agency receives payment from its customers. In these circumstances, the Company evaluates the credit worthiness of the agency’s customers, in addition to the agency itself, to conclude whether or not collectability is reasonably assured. If the Company determines collectability is not reasonably assured, the Company defers the revenue recognition until collectability becomes reasonably assured. The Company applies the authoritative accounting guidance regarding revenue recognition for arrangements with multiple deliverables. Professional services and training, when sold with the Company’s platform subscription services, are accounted for separately when those services have standalone value. In determining whether professional services and training services can be accounted for separately from subscription services, the Company considers the following factors: availability of the services from other vendors; the nature of the services; the dependence of the subscription services on the customer’s decision to buy the professional services; and whether the Company sells the Company’s subscription services without professional services. If the deliverables have stand-alone value, the Company accounts for each deliverable separately and revenues are recognized for the respective deliverables as they are delivered. If one or more of the deliverables do not have stand-alone value, the deliverables that do not have stand-alone value are combined with the final deliverables within the arrangement and treated as a single unit of accounting. Revenues for arrangements treated as a single unit of accounting are recognized over the period of the contract commencing upon delivery of the final deliverable. As of December 31, 2017, the Company did not have stand-alone value for the professional services and training services. This is because the Company includes professional services and training services with the Company’s subscription services and those services are not available from other vendors.
Cost of Revenues	Cost of Revenues Cost of revenues primarily consists of costs related to hosting the Company’s cloud-based platform, providing implementation and ongoing customer support, data communications expenses, salaries and benefits of operations and support personnel, software license fees, costs associated with website development activities, indirect overhead, amortization expense associated with capitalized internally developed software and intangible assets and property and equipment depreciation.
Stock-Based Compensation Expense	Stock-Based Compensation Expense Stock-based compensation expense is measured at grant date based on the fair value of the award and is expensed on a straight-line basis over the requisite service period. Fair values of stock option awards are determined on the date of grant using the Black-Scholes option-pricing model. In applying this option-pricing model, the Company’s determination of the fair value of the stock option award on the date of grant is affected by the Company’s fair value of its common stock, as well as assumptions regarding a number of subjective variables. These variables include, but are not limited to, the Company’s expected stock price volatility and the optionholders’ actual and projected stock option exercise and employment termination behaviors. RSUs are measured based on the fair market values of the underlying common stock on the dates of grant. Shares of common stock are issued on the vesting dates. For stock option and RSU awards with time-based vesting, the Company recognizes stock-based compensation expense over the requisite service period using the straight-line method, based on awards ultimately expected to vest. The Company estimates future forfeitures at the date of grant and revises the estimates, if necessary, in subsequent periods if actual forfeitures differ from those estimates. See Note 10 and Note 11 for further information.
Research and Development	Research and Development Research and development costs are expensed as incurred, except for certain internal software development costs, which may be capitalized as noted above. Research and development costs include salaries, stock-based compensation expense, benefits and other operating costs such as outside services, supplies and allocated overhead costs.
Advertising and Promotion	Advertising and Promotion Advertising and promotional costs are expensed as incurred and included in sales and marketing expense in the accompanying consolidated statements of comprehensive loss. Advertising and promotion expense totaled $758, $876, and $1,000 for 2017, 2016 and 2015, respectively.
Sales Taxes	Sales Taxes Sales and other taxes collected from customers and remitted to governmental authorities are presented on a net basis and thus excluded from revenues.
Foreign Currency	Foreign Currency For international subsidiaries whose functional currency is not the United States Dollar, we re-measure the monetary assets and liabilities of these subsidiaries to United States Dollars using rates of exchange in effect at the balance sheet date. Nonmonetary assets and liabilities are re-measured to United States Dollars using historical exchange rates, and other accounts are re-measured using average exchange rates in effect during each period presented. The effects of foreign currency translation adjustments are included in stockholders’ equity as a component of accumulated other comprehensive loss on the accompanying consolidated balance sheets, and related periodic movements are summarized as a line item in the consolidated statements of comprehensive loss. The Company records net gains and losses resulting from foreign exchange transactions as a component of other income (expenses), net. Aggregate foreign currency (losses) gains included in determining net loss were $(1,029), $(3) and $256 during 2017, 2016 and 2015, respectively.
Income Taxes	Income Taxes The Company accounts for income taxes using the asset and liability method. Under this method, deferred tax assets and liabilities are determined based on differences between the financial statement and tax basis of assets and liabilities and net operating loss and credit carryforwards using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized. The Company accounts for uncertain tax positions using a more-likely-than-not threshold for financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. The Company establishes a liability for tax-related uncertainties based on estimates of whether, and the extent to which, additional taxes will be due. The Company records an income tax liability, if any, for the difference between the benefit recognized and measured and the tax position taken or expected to be taken on the Company’s tax returns. To the extent that the assessment of such tax positions changes, the change in estimate is recorded in the period in which the determination is made. The liability is adjusted in light of changing facts and circumstances, such as the outcome of a tax audit. The provision for income taxes includes changes to the liabilities that are considered appropriate. The Company would recognize interest and penalties related to uncertain tax positions as income tax expense, though no such amounts were recognized in 2017, 2016 or 2015. As the Company maintained a full valuation allowance against its deferred tax assets in the United States, the adjustments resulted in no additional tax expense in 2017. The Company does not expect that changes in the liability for uncertain tax positions for the next twelve months will have a material impact on the Company’s consolidated financial position or results of operations. See Note 12 for information related to the enactment of the Tax Cuts and Jobs act in December 2017.
Out-of-Period Adjustment	Out of Period Adjustment During the year ended December 31, 2017, the Company recorded an out-of-period adjustment to correct previously overstated revenues related to its display product offering. These overstated revenues had accumulated since the Company’s acquisition in June 2014 of NowSpots, Inc., which conducted business as Perfect Audience, and the out-of-period adjustment resulted in a decrease to revenues in the amount of $400 for the year ended December 31, 2017. Management determined that this adjustment was not material to the Company’s consolidated financial statements for the year ended December 31, 2017, nor to any previously issued consolidated financial statements.
Recent Accounting Pronouncements Adopted in 2017	Recent Accounting Pronouncements Adopted in 2017 In January 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2017-04, Intangibles – Goodwill and Other: Simplifying the Accounting for Goodwill Impairment In March 2016, the FASB issued ASU 2016-09, Compensation - Stock Compensation: Improvements to Employee Share-Based Payment Accounting
Recent Accounting Pronouncements Not Yet Effective	Recent Accounting Pronouncements Not Yet Effective In May 2017, the FASB issued ASU 2017-09, Compensation – Stock Compensation In February 2016, the FASB issued ASU 2016-02, Leases In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers The Company will adopt the new guidance on January 1, 2018 using the modified retrospective approach, which will result in an adjustment to accumulated deficit for the cumulative effect of applying this standard to contracts in process as of the adoption date. Under this approach, the Company will not revise the prior financial statements presented, but will provide additional disclosures of the amount by which each financial statement line item is affected in the current reporting period during 2018 as a result of applying the new revenue guidance. This will include a qualitative explanation of the significant changes between the reported results under the revenue standard and the previous guidance. The Company has substantially completed its assessment of the potential impact this guidance will have on its consolidated financial statements and related disclosures. Based on that assessment, the Company currently expects the most significant impact of this new guidance will be the capitalization of costs to both obtain and fulfill contracts, which are expected to result in adjustments of approximately $1,800 and $900, respectively, to decrease the opening balance of Accumulated deficit upon adoption. Under previous accounting guidance, these costs were expensed as incurred. The Company also expects to begin recognizing breakage revenues from its arrangements with customers that prepay their advertising spend via credit card, based on historical breakage percentages. The Company does not expect the new guidance to have any further impact on its subscription revenues, as the identified performance obligations are substantially comparable to the deliverables and units of accounts identified under previous guidance.

Summary of Significant Accoun25

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Changes in Allowance for Doubtful Accounts	The following are changes in the allowance for doubtful accounts during 2017, 2016 and 2015, respectively. Years Ended December 31, 2017 2016 2015 Balances at beginning of year $ 3,510 $ 2,188 $ 989 Additions to expense 1,507 2,328 1,210 Additions against goodwill — — 442 Write-offs and other deductions (989 ) (1,006 ) (453 ) Balances at end of year $ 4,028 $ 3,510 $ 2,188

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Summary of Fair Values of Tangible Assets Acquired, Liabilities Assumed, Intangible Assets and Residual Goodwill	The following table summarizes the fair values of tangible assets acquired, liabilities assumed, intangible assets and residual goodwill from the acquisition of SocialMoov (in thousands, except years): Estimated Fair Value Estimated Useful Life Tangible assets acquired $ 2,741 N/A Liabilities assumed (Note 8) (3,627 ) N/A Developed technology 3,800 5 years Customer relationships 2,080 4 years Tradename 260 3 years Goodwill 8,034 Indefinite Total purchase price $ 13,288

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Components of Property and Equipment	The following table shows the components of property and equipment as of the dates presented: December 31, Estimated Useful Life 2017 2016 Computer equipment 3 years $ 29,938 $ 28,905 Software, including internally developed software 3 years 23,389 21,323 Leasehold improvements Shorter of useful life or lease term 4,617 4,613 Office equipment, furniture and fixtures 3 to 5 years 2,127 2,284 60,071 57,125 Less: Accumulated depreciation and amortization (44,512 ) (36,544 ) $ 15,559 $ 20,581
Components of Accrued Expenses and Other Current Liabilities	The following table shows the components of accrued expenses and other current liabilities as of the dates presented: December 31, 2017 2016 Accrued salary and payroll-related expenses $ 4,372 $ 3,894 Accrued accounts payable 2,161 1,915 Customer advances 2,003 1,582 Deferred rent 475 408 Sales and use tax payable 341 210 Income taxes payable 142 — Other 521 353 $ 10,015 $ 8,362

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The activity for the year ended December 31, 2017 consisted of the following: Balance at December 31, 2016 $ 19,318 Impairment (2,797 ) Foreign currency translation adjustments 247 Balance at December 31, 2017 $ 16,768
Schedule of Intangible Assets	Intangible assets consisted of the following as of the dates presented (in thousands except years): December 31, 2017 December 31, 2016 Estimated Useful Life Developed technology $ 9,910 $ 9,910 5 to 6 years Customer relationships 3,370 3,370 4 years Non-compete agreements and tradenames 1,390 1,390 2 to 3 years 14,670 14,670 Less: accumulated amortization (10,195 ) (7,345 ) $ 4,475 $ 7,325
Schedule of Future Estimated Amortization Costs of Intangible Assets	Future estimated amortization of intangible assets as of December 31, 2017 is presented below: Year ending December 31, 2018 $ 2,537 Year ending December 31, 2019 1,843 Year ending December 31, 2020 95 $ 4,475

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Account Balances Measured at Fair Value on Recurring Basis	Account balances measured at fair value on a recurring basis include the following as of the dates presented: December 31, 2017 2016 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Cash equivalents Money market funds $ 8,831 $ — $ — $ 15,657 $ — $ —

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Maturities of Capital Lease Obligations	The maturities of capital lease obligations as of December 31, 2017 are as follows: Year Ending December 31, 2018 $ 1,416 December 31, 2019 1,137 December 31, 2020 538 December 31, 2021 12 3,103 Less: Current portion (1,416 ) Capital lease obligations, non-current $ 1,687

Common Stock (Tables)

Common Stock (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Reserved Shares of Common Stock	Reserved shares of common stock are as follows for the dates presented: December 31, 2017 2016 Options or RSUs available for future grant under stock option plans 999 839 Options outstanding under stock option plans 436 536 RSUs outstanding under stock option plans 568 429 Shares available for future issuance under employee stock purchase plan 182 170 Shares to be issued in connection with acquisition of SocialMoov — 66 2,185 2,040

Equity Award Plans (Tables)

Equity Award Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Activity under the 2006 Plan and 2013 Plan	A summary of activity under the 2006 Plan and the 2013 Plan is as follows (in thousands, except per share amounts and years): Options Outstanding Number of Shares Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term (in Years) Aggregate Intrinsic Value Balance at December 31, 2014 911 $ 55.93 7.82 $ 9,697 Options granted 329 40.95 7.70 Options exercised (104 ) 13.86 — Options forfeited and cancelled (285 ) 62.44 — Balance at December 31, 2015 851 $ 53.06 7.85 $ 957 Options granted 172 18.62 6.82 Options exercised (38 ) 10.36 — Options forfeited and cancelled (449 ) 54.53 — Balance at December 31, 2016 536 $ 43.83 7.48 $ 194 Options granted 79 11.66 9.35 Options forfeited and cancelled (179 ) 44.82 — Balance at December 31, 2017 436 $ 37.60 7.04 $ 65 Options exercisable as of December 31, 2017 303 $ 45.97 6.25 $ 43 Options vested as of December 31, 2017 302 $ 45.96 6.25 $ 43 Options vested and expected to vest as of December 31, 2017 427 $ 37.96 7.01 $ 64
Summary of RSUs Granted and Unvested under the 2013 Plan	A summary of RSUs granted and unvested under the 2013 Plan during 2017 and 2016 is as follows (in thousands, except per unit amounts): RSUs Outstanding Number of Shares Weighted Average Grant Date Fair Value Per Unit Granted and unvested at December 31, 2014 110 $ 65.52 RSUs granted 169 39.76 RSUs vested (20 ) 68.81 RSUs cancelled (84 ) 54.53 Granted and unvested at December 31, 2015 175 $ 65.52 RSUs granted 446 18.76 RSUs vested (30 ) 50.33 RSUs cancelled and withheld to cover taxes (162 ) 30.80 Granted and unvested at December 31, 2016 429 $ 21.48 RSUs granted 405 10.56 RSUs vested, net (78 ) 21.29 RSUs cancelled and withheld to cover taxes (188 ) 19.97 Granted and unvested at December 31, 2017 568 $ 14.22

Stock-Based Compensation Expe33

Stock-Based Compensation Expense (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Assumptions Used to Estimate Fair Value of Options	The Company used the following assumptions: Years Ended December 31, 2017 2016 2015 Dividend yield — — — Expected volatility 47.3 % 47.5 % 49.1 % Risk-free interest rate 2.03 % 1.38 % 1.75 % Expected life of options (in years) 6.25 6.25 6.25 Weighted-average grant-date fair value $ 5.61 $ 8.82 $ 20.16 Weighted-average grant-date exercise price $ 11.66 $ 18.62 $ 40.95

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Components of Loss Before Provision for Income Taxes	The components of the Company’s loss before provision for income taxes were as follows: Years Ended December 31, 2017 2016 2015 United States of America $ (15,740 ) $ (7,595 ) $ (17,173 ) International (14,744 ) (7,481 ) (15,171 ) $ (30,484 ) $ (15,076 ) $ (32,344 )
Schedule of Components of Provision for Income Taxes	The components of the provision for income taxes were as follows: Years Ended December 31, 2017 2016 2015 Current income tax provision Federal $ — $ — $ — State 64 58 111 Foreign 1,301 1,708 1,193 Total current income tax provision 1,365 1,766 1,304 Deferred income tax benefit Federal — — - State — — - Foreign (358 ) (362 ) (299 ) Total deferred income tax benefit (358 ) (362 ) (299 ) Provision for income taxes $ 1,007 $ 1,404 $ 1,005
Differences in Total Provision for Income Taxes	The differences in the total provision for income taxes that would result from applying the 34% federal statutory rate to loss before provision for income taxes and the reported provision for income taxes were as follows: Years Ended December 31, 2017 2016 2015 Tax benefit at U.S. statutory rate $ (10,365 ) $ (5,126 ) $ (10,997 ) State income taxes, net of federal benefit (2,858 ) (147 ) (104 ) Foreign income and withholding taxes 5,578 4,317 6,033 Impact of change to U.S. statutory rate from Tax Cuts and Jobs Act 14,302 — — Stock-based compensation 1,085 2,231 1,039 Change in valuation allowance (8,158 ) 155 3,807 Research and development credits (382 ) (736 ) (1,067 ) Uncertain tax positions 1,995 1,146 1,277 Provision to return adjustments 153 (484 ) 848 Impact of adoption of ASU 2016-09 (1,291 ) — — Other 948 48 169 $ 1,007 $ 1,404 $ 1,005
Schedule of Components of Company's Deferred Tax Assets (Liabilities)	Major components of the Company’s deferred tax assets (liabilities) as of December 31, 2017 and 2016 are as follows: December 31, 2017 2016 Net operating loss $ 25,002 $ 32,551 Accruals and reserves 1,656 2,934 Research and development credits 8,757 7,368 Stock-based compensation 2,796 4,622 Property and equipment and intangible assets (710 ) (1,855 ) Other 3,161 2,842 Net deferred tax assets 40,662 48,462 Valuation allowance (41,224 ) (49,382 ) Total non-current net deferred tax liabilities, net of valuation allowance $ (562 ) $ (920 )
Change in Uncertain Tax Positions	The aggregate changes in the balance of gross uncertain tax positions were as follows: Ending balance as of December 31, 2014 $ 1,581 Increase in balances related to tax positions taken during the current period 3,196 Increase in balances related to tax positions taken during the prior period 2,781 Ending balance as of December 31, 2015 7,558 Decrease in balances related to tax positions taken during the current period (2 ) Increase in balances related to tax positions taken during the prior period 1,240 Ending balance as of December 31, 2016 8,796 Increase in balances related to tax positions taken during the current period 1,738 Decrease in balances related to tax positions taken during the prior period (9 ) Decrease in balances due to change in United States statutory rate (2,101 ) Ending balance as of December 31, 2017 $ 8,424

Net Loss Per Share Available 35

Net Loss Per Share Available to Common Stockholders (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Calculation of Basic and Diluted Net Loss Per Share	The following table presents the calculation of basic and diluted net loss per share for the periods presented (in thousands except per share amounts): Years Ended December 31, 2017 2016 2015 Numerator: Net loss available to common stockholders $ (31,491 ) $ (16,480 ) $ (33,349 ) Denominator: Weighted average number of shares, basic and diluted 5,638 5,474 5,225 Net loss per share available to common stockholders: Basic and diluted net loss per common share available to common stockholders $ (5.59 ) $ (3.01 ) $ (6.38 )
Potential Common Shares Outstanding	The following table presents the potential common shares outstanding that were excluded from the computation of diluted net loss per share available to common stockholders for the periods presented because including them would have been anti-dilutive: Years Ended December 31, 2017 2016 2015 Options to purchase common stock 436 536 851 RSUs 568 429 175 Restricted common stock — — 19 Common stock subject to repurchase — 1 3 1,004 966 1,048

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Revenues by Geographic Area, Based on Billing Location of Customer and Long-Lived Assets, by Geographical Areas	Revenues by geographic area, based on the billing location of the customer, were as follows: Years Ended December 31, 2017 2016 2015 United States of America $ 49,637 $ 69,220 $ 72,942 International 25,354 30,658 35,588 Total revenues, net $ 74,991 $ 99,878 $ 108,530 Long-lived assets, excluding goodwill and intangible assets, by geographic area were as follows: December 31, 2017 2016 United States of America $ 15,069 $ 19,861 International 490 720 Total long-lived assets, net $ 15,559 $ 20,581

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Annual Future Minimum Payments under Operating Leases	Future minimum lease payments for significant operating leases, net of sublease payments, as of December 31, 2017 were as follows: Year Ending December 31, 2018 $ 7,439 December 31, 2019 7,986 December 31, 2020 3,664 December 31, 2021 3,444 December 31, 2022 2,211 Thereafter 475 $ 25,219

Background - Additional Informa

Background - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017
Background And Business Description [Abstract]
Incorporation date	Mar. 31, 2006

Summary of Significant Accoun39

Summary of Significant Accounting Policies - Additional Information (Detail)	Oct. 05, 2017shares	Jan. 01, 2017USD ($)	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)shares	Dec. 31, 2017USD ($)Customershares	Dec. 31, 2016USD ($)Customershares	Dec. 31, 2015USD ($)Customer	Oct. 04, 2017shares	Dec. 31, 2014USD ($)
Summary Of Significant Accounting Policies [Line Items]
Net loss					$ (31,491,000)	$ (16,480,000)	$ (33,349,000)
Accumulated deficit				$ (227,704,000)	(227,704,000)	(196,213,000)
Cash, cash equivalents and restricted cash				$ 28,837,000	$ 28,837,000	$ 35,713,000	37,326,000		$ 68,253,000
Number of fractional shares issued in connection with reverse stock split | shares	0
Common stock, shares authorized | shares	142,857,000			142,857,000	142,857,000	142,857,000		500,000,000
Convertible preferred stock, shares authorized | shares	0			10,000,000	10,000,000	10,000,000
Cash equivalent consist of money market with maturity dates					90 days	90 days
Cash equivalents				$ 8,831,000	$ 8,831,000	$ 15,657,000
Allowance for potential customer credits				799,000	799,000	1,947,000
Capitalization of internally developed software costs					2,068,000	4,712,000	5,568,000
Amortization of internally developed software					3,669,000	2,988,000	2,550,000
Unamortized internally developed software costs				8,617,000	8,617,000	10,218,000
Impairment of goodwill			$ 2,797,000	0
Impairment losses on long-lived assets					0	0	0
Advertising and promotion expense					758,000	876,000	1,000,000
Gains losses from foreign exchange transactions					(1,029,000)	(3,000)	256,000
Interest or penalties related to uncertain tax positions				0	0	0	0
Additional tax expense					0
Out-of-period revenue adjustment					400,000
Increase in valuation allowance					(8,158,000)	469,000	$ 5,467,000
Decrease in accumulated deficit				$ 1,800,000	$ 1,800,000	$ 900,000
ASU 2016-09 [Member]
Summary Of Significant Accounting Policies [Line Items]
Increase in valuation allowance		$ 1,423,000
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangible assets amortized useful lives					2 years
Minimum [Member] | Subscription arrangement [Member]
Summary Of Significant Accounting Policies [Line Items]
Length of subscription agreements					1 year
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangible assets amortized useful lives					6 years
Software [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of internally developed software					3 years
Concentration of Credit Risk [Member] | Accounts Receivable [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of customers accounted for greater than 10% | Customer					0	0
Concentration of Credit Risk [Member] | Revenues [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of customers accounted for greater than 10% | Customer					0	0	0
Common Stock [Member]
Summary Of Significant Accounting Policies [Line Items]
Net loss					$ 0	$ 0	$ 0
Reverse stock split of common stock, description	On October 5, 2017, the Company effected a reverse stock split of its outstanding common stock. As a result of the reverse stock split, each seven outstanding shares of the Company’s common stock were combined into one outstanding share of common stock, without any change in par value. The common stock began trading on the New York Stock Exchange on a split-adjusted basis on October 6, 2017. No fractional shares were issued in connection with the reverse stock split and the Company paid in cash the fair value of such fractional shares.
Reverse stock split of common stock, conversion ratio	0.143

Summary of Significant Accoun40

Summary of Significant Accounting Policies - Changes in Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Balances at beginning of year	$ 3,510	$ 2,188	$ 989
Additions to expense	1,507	2,328	1,210
Additions against goodwill	0	0	442
Write-offs and other deductions	(989)	(1,006)	(453)
Balances at end of year	$ 4,028	$ 3,510	$ 2,188

Business Combinations - Additio

Business Combinations - Additional Information (Detail) - USD ($) shares in Thousands, $ in Thousands	Feb. 12, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Purchase price attributable to goodwill		$ 16,768	$ 19,318
Number of RSUs, granted		405	446	169
SocialMoov [Member]
Business Acquisition [Line Items]
Acquisition date		Feb. 12, 2015
Business acquisition, purchase price	$ 13,288
Number of common stock, shares at the date of acquisition	91
Consideration in common stock	$ 4,337
Common stock value at the date of acquisition	8,858
Cash paid as contingent consideration			$ 93
Purchase price of net liabilities assumed	2,006	$ 3,627
Cash acquired from acquisition	1,120
Purchase price attributable to intangible assets	6,140
Purchase price attributable to goodwill	$ 8,034	$ 8,034
Additional shares of common stock issued in connection with acquisition	132
Common stock issued in connection with acquisition closing date fair value	$ 6,487
Additional shares of common stock issued in connection with acquisition, description		In addition, the Company agreed to issue 132 shares of common stock, valued at $6,487 upon the closing date of the acquisition using the Company’s closing date stock price immediately preceding the acquisition, to existing employee shareholders of SocialMoov in connection with the acquisition, which were conditioned upon such employees’ continuous employment with the Company. These shares were excluded from the purchase consideration and were recognized as post-acquisition stock-based compensation expense over the employees’ requisite service periods. The Company issued half of these shares in February 2016 and the remaining half in February 2017.
SocialMoov [Member] | RSUs [Member]
Business Acquisition [Line Items]
Number of RSUs, granted	31
Value of RSUs, granted	$ 959

Business Combinations - Summary

Business Combinations - Summary of Fair Values of Tangible Assets Acquired, Liabilities Assumed, Intangible Assets and Residual Goodwill (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Feb. 12, 2015
Business Acquisition [Line Items]
Goodwill	$ 16,768	$ 19,318
Customer relationships [Member]
Business Acquisition [Line Items]
Intangible assets, Estimated Useful Life	4 years
SocialMoov [Member]
Business Acquisition [Line Items]
Tangible assets acquired	$ 2,741
Liabilities assumed (Note 8)	(3,627)		$ (2,006)
Goodwill	8,034		$ 8,034
Total purchase price	$ 13,288
Goodwill, Estimated Useful Life	Indefinite
SocialMoov [Member] | Developed technology [Member]
Business Acquisition [Line Items]
Intangible assets, Estimated Fair Value	$ 3,800
Intangible assets, Estimated Useful Life	5 years
SocialMoov [Member] | Customer relationships [Member]
Business Acquisition [Line Items]
Intangible assets, Estimated Fair Value	$ 2,080
Intangible assets, Estimated Useful Life	4 years
SocialMoov [Member] | Tradename [Member]
Business Acquisition [Line Items]
Intangible assets, Estimated Fair Value	$ 260
Intangible assets, Estimated Useful Life	3 years

Restructuring Activities - Addi

Restructuring Activities - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
2016 Restructuring Plan [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring related expenses	$ 0	$ 596,000
2015 Restructuring Plans [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring related expenses	$ 0	$ 0	$ 1,214,000

Balance Sheet Components - Comp

Balance Sheet Components - Components of Property and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 60,071	$ 57,125
Less: Accumulated depreciation and amortization	(44,512)	(36,544)
Property and equipment, net	$ 15,559	20,581
Computer Equipment [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of property and equipment	3 years
Property and equipment, gross	$ 29,938	28,905
Software, Including Internally Developed Software [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of property and equipment	3 years
Property and equipment, gross	$ 23,389	21,323
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of property and equipment	Shorter of useful life or lease term
Property and equipment, gross	$ 4,617	4,613
Office Equipment, Furniture and Fixtures [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 2,127	$ 2,284
Office Equipment, Furniture and Fixtures [Member] | Minimum [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of property and equipment	3 years
Office Equipment, Furniture and Fixtures [Member] | Maximum [Member]
Property Plant And Equipment [Line Items]
Estimated useful life of property and equipment	5 years

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Depreciation and amortization of internally developed software	$ 8,427	$ 9,023	$ 9,543

Balance Sheet Components - Co46

Balance Sheet Components - Components of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accrued Liabilities And Other Liabilities [Abstract]
Accrued salary and payroll-related expenses	$ 4,372	$ 3,894
Accrued accounts payable	2,161	1,915
Customer advances	2,003	1,582
Deferred rent	475	408
Sales and use tax payable	341	210
Income taxes payable	142	0
Other	521	353
Accrued expenses and other current liabilities	$ 10,015	$ 8,362

Goodwill and Intangible Asset47

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill	$ 16,768,000	$ 16,768,000	$ 19,318,000
Impairment of goodwill	$ 0	2,797,000	0	$ 0
Amortization of intangible assets		$ 2,850,000	$ 3,080,000	$ 3,134,000

Goodwill and Intangible Asset48

Goodwill and Intangible Assets - Schedule of Goodwill (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Balance at December 31, 2016		$ 19,318,000
Impairment	$ 0	(2,797,000)	$ 0	$ 0
Foreign currency translation adjustments		247,000
Balance at December 31, 2017	$ 16,768,000	$ 16,768,000	$ 19,318,000

Goodwill and Intangible Asset49

Goodwill and Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Finite Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 14,670	$ 14,670
Less: accumulated amortization	(10,195)	(7,345)
Intangible assets, net	$ 4,475	7,325
Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets amortized useful lives	2 years
Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets amortized useful lives	6 years
Developed technology [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 9,910	9,910
Developed technology [Member] | Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets amortized useful lives	5 years
Developed technology [Member] | Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets amortized useful lives	6 years
Customer relationships [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 3,370	3,370
Intangible assets amortized useful lives	4 years
Non-compete agreements and tradename [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 1,390	$ 1,390
Non-compete agreements and tradename [Member] | Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets amortized useful lives	2 years
Non-compete agreements and tradename [Member] | Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets amortized useful lives	3 years

Goodwill and Intangible Asset50

Goodwill and Intangible Assets - Schedule of Future Estimated Amortization Costs of Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Year ending December 31, 2018	$ 2,537
Year ending December 31, 2019	1,843
Year ending December 31, 2020	95
Intangible assets, net	$ 4,475	$ 7,325

Fair Value Measurements - Accou

Fair Value Measurements - Account Balances Measured at Fair Value on Recurring Basis (Detail) - Fair Value Measurements Recurring [Member] - Money Market Funds [Member] - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Level 1 [Member]
Cash equivalents
Cash equivalents - Money market funds	$ 8,831	$ 15,657
Level 2 [Member]
Cash equivalents
Cash equivalents - Money market funds	0	0
Level 3 [Member]
Cash equivalents
Cash equivalents - Money market funds	$ 0	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Unrealized gains or losses on money market funds	$ 0	$ 0
Amount held in bank deposits	$ 18,713	$ 18,763

Debt - Additional Information (

Debt - Additional Information (Detail)	1 Months Ended	2 Months Ended	12 Months Ended	26 Months Ended
	Jul. 31, 2015USD ($)	Oct. 31, 2016InstallmentLease	Dec. 31, 2017USD ($)	Sep. 30, 2017InstallmentLease	Dec. 31, 2016USD ($)	Feb. 28, 2015USD ($)	Dec. 31, 2014USD ($)
Line Of Credit Facility [Line Items]
Restrict from use in cash held at Silicon Valley Bank			$ 1,293,000		$ 1,293,000
SocialMoov loans [Member]
Line Of Credit Facility [Line Items]
Loans payables						$ 1,043,000
Capital Lease for Acquisition of Computer Equipment [Member]
Line Of Credit Facility [Line Items]
Effective annual interest rate		5.20%
Number of monthly installments | Installment		48
Number of capital lease arrangements | Lease		2		9
Net book value of equipment under capital leases			2,861,000		3,158,000
Remaining principal balance payable			$ 3,103,000		3,411,000
Capital Lease for Acquisition of Computer Equipment [Member] | Minimum [Member]
Line Of Credit Facility [Line Items]
Effective annual interest rate				5.70%
Number of monthly installments | Installment				36
Capital Lease for Acquisition of Computer Equipment [Member] | Maximum [Member]
Line Of Credit Facility [Line Items]
Effective annual interest rate				7.90%
Number of monthly installments | Installment				48
Revolving Credit Facility [Member]
Line Of Credit Facility [Line Items]
Credit facility	$ 20,000,000
Percentage of eligible accounts receivable	80.00%
Revolving credit facility, the expiration date	Jul. 31, 2017
Revolving credit facility, amended annual interest rate	2.75%
Revolving credit facility, amount outstanding					0
Line of credit facility termination month and year			2016-12
Letter of Credit [Member]
Line Of Credit Facility [Line Items]
Credit facility							$ 1,293,000
Restrict from use in cash held at Silicon Valley Bank					$ 1,293,000

Debt - Maturities of Capital Le

Debt - Maturities of Capital Lease Obligations (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
December 31, 2018	$ 1,416
December 31, 2019	1,137
December 31, 2020	538
December 31, 2021	12
Total	3,103
Current portion	(1,416)	$ (1,015)
Capital lease obligations, non-current	$ 1,687	$ 2,381

Common Stock - Additional Infor

Common Stock - Additional Information (Detail) - $ / shares	Dec. 31, 2017	Oct. 05, 2017	Oct. 04, 2017	Dec. 31, 2016
Equity [Abstract]
Common stock, shares authorized	142,857,000	142,857,000	500,000,000	142,857,000
Common stock, par value	$ 0.001			$ 0.001
Convertible preferred stock, shares authorized	10,000,000	0		10,000,000
Convertible preferred stock, par value	$ 0.001			$ 0.001

Common Stock - Reserved Shares

Common Stock - Reserved Shares of Common Stock (Detail) - shares shares in Thousands	Dec. 31, 2017	Dec. 31, 2016	Feb. 28, 2013
Class Of Stock [Line Items]
Reserved shares of Common Stock	2,185	2,040
Shares Available for Future Issuance under Employee Stock Purchase Plan [Member]
Class Of Stock [Line Items]
Reserved shares of Common Stock	182	170	143
RSUs [Member]
Class Of Stock [Line Items]
Reserved shares of Common Stock	568	429
Options Outstanding [Member]
Class Of Stock [Line Items]
Reserved shares of Common Stock	436	536
Shares to be Issued in Connection with Acquisition of SocialMoov [Member]
Class Of Stock [Line Items]
Reserved shares of Common Stock	0	66
Options or RSUs Available for Future Grant [Member]
Class Of Stock [Line Items]
Reserved shares of Common Stock	999	839

Equity Award Plans - Additional

Equity Award Plans - Additional Information (Detail) - USD ($) $ in Thousands	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Feb. 28, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Reserved shares of Common Stock		2,185,000	2,040,000
Intrinsic value of options exercised			$ 328	$ 2,935
Estimated fair value of share options vested		$ 1,451	$ 5,424	$ 7,573
2013 Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Reserved shares of Common Stock		182,000	170,000		143,000
Percentage of shares outstanding under Equity Award Plan		1.00%
Increase in common stock available for issuance	57,000
Percentage of fair market value of common stock of lesser		85.00%
Shares issued under 2013 ESPP		43,000	42,000
Number of shares reserved under Employee Stock Purchase Plan		100,000
Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options, vest period		10 years
Employee Stock Plan 2006 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options, vest period		10 years
Repurchase of common stock		0	1,000
Long-term liability		$ 4	$ 41
2013 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Reserved shares of Common Stock					643,000
Percentage of shares outstanding under Equity Award Plan		5.00%
2013 Equity Incentive Plan [Member] | Subsequent Event [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in common stock available for issuance	286,000
Reason Other Than Disability or Death [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise period of options		3 months
Due to Disability or Death [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise period of options		12 months

Equity Award Plans - Summary of

Equity Award Plans - Summary of Activity under the 2006 Plan and 2013 Plan (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares, Options Outstanding, Balance	536	851	911
Number of Shares, Options Granted	79	172	329
Number of Shares, Options Exercised		(38)	(104)
Number of Shares, Options Forfeited and Cancelled	(179)	(449)	(285)
Number of Shares, Options Outstanding, Balance	436	536	851	911
Number of Shares, Options Exercisable, Balance	303
Number of Shares, Options Vested, Balance	302
Number of Shares, Options Vested and Expected to Vest, Balance	427
Weighted Average Exercise Price Per Share, Options Outstanding, Balance	$ 43.83	$ 53.06	$ 55.93
Weighted Average Exercise Price Per Share, Options granted	11.66	18.62	40.95
Weighted Average Exercise Price Per Share, Options exercised		10.36	13.86
Weighted Average Exercise Price Per Share, Options forfeited and cancelled	44.82	54.53	62.44
Weighted Average Exercise Price Per Share, Options Outstanding, Balance	37.60	$ 43.83	$ 53.06	$ 55.93
Weighted Average Exercise Price Per Share, Options exercisable, Balance	45.97
Weighted Average Exercise Price Per Share, Options vested, Balance	45.96
Weighted Average Exercise Price Per Share, Options vested and expected to vest, Balance	$ 37.96
Weighted Average Remaining Contractual Term, Options Outstanding (in years)	7 years 14 days	7 years 5 months 23 days	7 years 10 months 6 days	7 years 9 months 25 days
Weighted Average Remaining Contractual Term, Options granted (in years)	9 years 4 months 6 days	6 years 9 months 25 days	7 years 8 months 12 days
Weighted Average Remaining Contractual Term, Options exercised (in years)		0 years	0 years
Weighted Average Remaining Contractual Term, Options forfeited and cancelled (in years)	0 years	0 years	0 years
Weighted Average Remaining Contractual Term, Options exercisable (in years)	6 years 3 months
Weighted Average Remaining Contractual Term, Options vested (in years)	6 years 3 months
Weighted Average Remaining Contractual Term, Options vested and expected to vest (in years)	7 years 3 days
Aggregate Intrinsic Value, Options Outstanding, Balance	$ 65	$ 194	$ 957	$ 9,697
Aggregate Intrinsic Value, Options exercisable, Balance	43
Aggregate Intrinsic Value, Options vested, Balance	43
Aggregate Intrinsic Value, Options vested and expected to vest, Balance	$ 64

Equity Award Plans - Summary 59

Equity Award Plans - Summary of RSUs Granted and Unvested under the 2013 Plan (Detail) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of RSUs, Granted and unvested, Beginning balance	429	175	110
Number of RSUs, granted	405	446	169
Number of RSUs, vested	(78)	(30)	(20)
Number of RSUs, cancelled	(188)	(162)	(84)
Number of RSUs, Granted and unvested, Ending balance	568	429	175
Weighted Average Grant Date Fair Value Per Unit, RSUs Granted and unvested, Beginning balance	$ 21.48	$ 65.52	$ 65.52
Weighted Average Grant Date Fair Value Per Unit, RSUs granted	10.56	18.76	39.76
Weighted Average grant Date Fair Value Per Unit, RSUs vested	21.29	50.33	68.81
Weighted Average Grant Date Fair Value Per Unit, RSUs cancelled	19.97	30.80	54.53
Weighted Average Grant Date Fair Value Per Unit, RSUs Granted and unvested, Ending balance	$ 14.22	$ 21.48	$ 65.52

Stock-Based Compensation Expe60

Stock-Based Compensation Expense - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 4,704,000	$ 10,295,000	$ 15,619,000
Proceeds from exercise of common stock options	0	390,000	$ 1,439,000
Unrecognized compensation cost, adjusted for estimated forfeitures, related to options	934,000	$ 2,706,000
Non Vested Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 0
Options Available for Future Grant [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Recognized weighted-average period	1 year 7 months 6 days	2 years 1 month 6 days
Restricted Stock and RSUs [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Recognized weighted-average period	2 years 1 month 6 days	2 years 3 months 18 days
Unrecognized compensation cost, adjusted for estimated forfeitures, related to restricted stock and RSUs	$ 6,428,000	$ 7,973,000

Stock-Based Compensation Expe61

Stock-Based Compensation Expense - Assumptions Used to Estimate Fair Value of Options (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Dividend yield	0.00%	0.00%	0.00%
Expected volatility	47.30%	47.50%	49.10%
Risk-free interest rate	2.03%	1.38%	1.75%
Expected life of options (in years)	6 years 3 months	6 years 3 months	6 years 3 months
Weighted-average grant-date fair value	$ 5.61	$ 8.82	$ 20.16
Weighted-average grant-date exercise price	$ 11.66	$ 18.62	$ 40.95

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Loss Before Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
United States of America	$ (15,740)	$ (7,595)	$ (17,173)
International	(14,744)	(7,481)	(15,171)
Loss before provision for income taxes	$ (30,484)	$ (15,076)	$ (32,344)

Income Taxes - Schedule of Co63

Income Taxes - Schedule of Components of Provision of Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current income tax provision
Federal	$ 0	$ 0	$ 0
State	64	58	111
Foreign	1,301	1,708	1,193
Total current income tax provision	1,365	1,766	1,304
Deferred income tax benefit
Federal	0	0	0
State	0	0	0
Foreign	(358)	(362)	(299)
Total deferred income tax benefit	(358)	(362)	(299)
Provision for income taxes	$ 1,007	$ 1,404	$ 1,005

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule Of Income Taxes [Line Items]
Federal statutory rate on loss before provision for income taxes		34.00%
Cumulative ownership percentage		50.00%
Cumulative ownership period		3 years
Increase (decrease) in valuation allowance		$ (8,158,000)	$ 469,000	$ 5,467,000
Interest or penalties related to uncertain tax positions		0	0	0
Uncertain tax positions that would impact effective tax rate		1,610,000	1,049,000
Re-measurement of deferred tax assets change in tax rate reduced amount		18,696,000
Re-measurement of deferred tax liabilities change in tax rate reduced amount		4,394,000
Adjustment to valuation allowance due to impact of tax cuts and jobs act		14,302,000	$ 0	$ 0
Scenario Forecast
Schedule Of Income Taxes [Line Items]
Federal statutory rate on loss before provision for income taxes	21.00%
Federal [Member]
Schedule Of Income Taxes [Line Items]
Net operating loss carryforwards		$ 110,087,000
Net operating loss carryforwards expiration date		2,026
State [Member]
Schedule Of Income Taxes [Line Items]
Net operating loss carryforwards		$ 91,585,000
Net operating loss carryforwards expiration date		2,022
Federal Research and Development [Member]
Schedule Of Income Taxes [Line Items]
Research and development credits		$ 6,139,000
Research and development credits expiration year		2,026
State Research and Development [Member]
Schedule Of Income Taxes [Line Items]
Research and development credits		$ 6,451,000
Foreign Tax Authority [Member] | French Tax Authority [Member] | Minimum [Member]
Schedule Of Income Taxes [Line Items]
Income tax examination year		2,012
Foreign Tax Authority [Member] | French Tax Authority [Member] | Maximum [Member]
Schedule Of Income Taxes [Line Items]
Income tax examination year		2,016

Income Taxes - Differences in T

Income Taxes - Differences in Total Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Tax benefit at U.S. statutory rate	$ (10,365)	$ (5,126)	$ (10,997)
State income taxes, net of federal benefit	(2,858)	(147)	(104)
Foreign income and withholding taxes	5,578	4,317	6,033
Impact of change to U.S. statutory rate from Tax Cuts and Jobs Act	14,302	0	0
Stock-based compensation	1,085	2,231	1,039
Change in valuation allowance	(8,158)	155	3,807
Research and development credits	(382)	(736)	(1,067)
Uncertain tax positions	1,995	1,146	1,277
Provision to return adjustments	153	(484)	848
Impact of adoption of ASU 2016-09	(1,291)	0	0
Other	948	48	169
Provision for income taxes	$ 1,007	$ 1,404	$ 1,005

Income Taxes - Schedule of Co66

Income Taxes - Schedule of Components of Company's Deferred Tax Assets (Liabilities) (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets Net Noncurrent Classification [Abstract]
Net operating loss	$ 25,002	$ 32,551
Accruals and reserves	1,656	2,934
Research and development credits	8,757	7,368
Stock-based compensation	2,796	4,622
Property and equipment and intangible assets	(710)	(1,855)
Other	3,161	2,842
Net deferred tax assets	40,662	48,462
Valuation allowance	(41,224)	(49,382)
Total non-current net deferred tax liabilities, net of valuation allowance	$ (562)	$ (920)

Income Taxes - Changes in Uncer

Income Taxes - Changes in Uncertain Tax Positions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Beginning balance	$ 8,796	$ 7,558	$ 1,581
Increase in balances related to tax positions taken during the current period	1,738		3,196
Decrease in balances related to tax positions taken during the current period		(2)
Increase in balances related to tax positions taken during the prior period		1,240	2,781
Decrease in balances related to tax positions taken during the prior period	(9)
Decrease in balances due to change in United States statutory rate	(2,101)
Ending balance	$ 8,424	$ 8,796	$ 7,558

Net Loss Per Share Available 68

Net Loss Per Share Available to Common Stockholders - Calculation of Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Numerator:
Net loss available to common stockholders	$ (31,491)	$ (16,480)	$ (33,349)
Denominator:
Weighted average number of shares, basic and diluted	5,638	5,474	5,225
Net loss per share available to common stockholders:
Basic and diluted net loss per common share available to common stockholders	$ (5.59)	$ (3.01)	$ (6.38)

Net Loss Per Share Available 69

Net Loss Per Share Available to Common Stockholders - Potential Common Shares Outstanding (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential common shares outstanding	1,004	966	1,048
RSUs [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential common shares outstanding	568	429	175
Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential common shares outstanding	436	536	851
Restricted Common Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential common shares outstanding	0	0	19
Common Stock Subject to Repurchase [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potential common shares outstanding	0	1	3

Segment Reporting - Additional

Segment Reporting - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017Segment
Segment Reporting [Abstract]
Number of operating segments	1
Number of reportable segment	1

Segment Reporting - Revenues by

Segment Reporting - Revenues by Geographic Area, Based on Billing Location of Customer and Long-Lived Assets, by Geographical Areas (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues, net	$ 74,991	$ 99,878	$ 108,530
Total long-lived assets, net	15,559	20,581
United States of America [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues, net	49,637	69,220	72,942
Total long-lived assets, net	15,069	19,861
International [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues, net	25,354	30,658	$ 35,588
Total long-lived assets, net	$ 490	$ 720

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Rent expense	$ 8,519	$ 8,760	$ 8,673
Non-cancelable operating leases, minimum year	2,018
Non-cancelable operating leases, maximum year	2,024
Liabilities obligations	$ 0	$ 0

Commitments and Contingencies73

Commitments and Contingencies - Annual Future Minimum Payments under Operating Leases (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Commitments And Contingencies Disclosure [Abstract]
Year ending December 31, 2018	$ 7,439
Year ending December 31, 2019	7,986
Year ending December 31, 2020	3,664
Year ending December 31, 2021	3,444
Year ending December 31, 2022	2,211
Thereafter	475
Future minimum lease payments for significant operating leases	$ 25,219

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions to employee benefit plans	$ 0	$ 0	$ 0
United Kingdom [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions to employee benefit plans	$ 75,000	$ 85,000	$ 93,000

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail) - Subsequent Event [Member] $ in Thousands	1 Months Ended
	Jan. 31, 2018USD ($)
Minimum [Member]
Subsequent Event [Line Items]
Pre-tax charges and restructuring costs	$ 1,000
Maximum [Member]
Subsequent Event [Line Items]
Pre-tax charges and restructuring costs	$ 1,500