Zeta Global (ZETA) 10-Q 10 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Oct. 29, 2021
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Document Quarterly Report	true
Document Transition Report	false
Entity Registrant Name	ZETA GLOBAL HOLDINGS CORP.
Entity Central Index Key	0001851003
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Trading Symbol	ZETA
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Small Business	false
Entity Interactive Data Current	Yes
Title of 12(b) Security	Class A common stock
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-40464
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	80-0814458
Entity Address, Address Line One	3 Park Ave, 33rd Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10016
City Area Code	212
Local Phone Number	967-5055
Common Class A [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		159,603,268
Common Class B [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		37,856,095

Condensed Unaudited Consolidate

Condensed Unaudited Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 116,180	$ 50,725
Accounts receivable, net of allowance of $2,046 and $2,207 as of September 30, 2021 and December 31, 2020, respectively	72,785	79,366
Prepaid expenses	5,820	3,903
Other current assets	3,058	7,374
Total current assets	197,843	141,368
Property and equipment, net	5,869	6,117
Website and software development costs, net	38,477	32,891
Intangible assets, net	28,932	28,591
Goodwill	81,917	76,432
Deferred tax assets,	195	366
Other non-current assets	1,063	521
Total non-current assets	156,453	144,918
Total assets	354,296	286,286
Current liabilities:
Accounts payable	27,905	40,976
Accrued expenses	50,619	44,622
Acquisition related liabilities	16,155	6,018
Deferred revenue	2,739	4,053
Other current liabilities	5,044	8,310
Total current liabilities	102,462	103,979
Non-current liabilities:
Long term borrowings	183,528	189,693
Acquisition related liabilities	8,731	17,137
Warrants and derivative liabilities		58,100
Other non-current liabilities	3,790	2,387
Total non-current liabilities	196,049	267,317
Total liabilities	298,511	371,296
Commitments and contingencies (Note 8)
Mezzanine equity
Redeemable convertible preferred stock $0.001 per share par value, up to 60,137,979 shares authorized and 39,223,194 shares issued and outstanding as of December 31, 2020		154,210
Treasury common stock, 8,195,464 shares repurchased at a weighted average price of $2.86 per share	(23,469)	(23,469)
Additional paid-in capital	511,929	28,425
Accumulated deficit	(430,679)	(242,254)
Accumulated other comprehensive loss	(2,189)	(2,037)
Total stockholders' equity / (deficit)	55,785	(239,220)
Total liabilities and stockholders' equity / (deficit)	354,296	286,286
Common Class A [Member]
Mezzanine equity
Common stock value	155
Total stockholders' equity / (deficit)	155
Common Class B [Member]
Mezzanine equity
Common stock value	38
Total stockholders' equity / (deficit)	$ 38
Series A Common Stock [Member]
Mezzanine equity
Common stock value		112
Total stockholders' equity / (deficit)		112
Series B Common Stock [Member]
Mezzanine equity
Common stock value		3
Total stockholders' equity / (deficit)		$ 3

Condensed Unaudited Consolida_2

Condensed Unaudited Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Accounts receivable, net of allowance	$ 2,046	$ 2,207
Redeemable Convertible Preferred Stock , Par or Stated Value Per Share		$ 0.001
Redeemable Convertible Preferred Stock , Shares Authorized		60,137,979
Redeemable Convertible Preferred Stock , Shares Issued		39,223,194
Redeemable Convertible Preferred Stock , Shares Outstanding		39,223,194
Treasury Stock Acquired, Average Cost Per Share	$ 2.86	$ 2.86
Treasury Stock, Shares, Acquired	8,195,464	8,195,464
Series A Common Stock [Member]
Common Stock, Par or Stated Value Per Share		$ 0.001
Common Stock, Shares Authorized		204,220,800
Common Stock, Shares, Issued		112,012,693
Common stock, shares, outstanding		112,012,693
Series B Common Stock [Member]
Common Stock, Par or Stated Value Per Share		$ 0.001
Common Stock, Shares Authorized		3,400,000
Common Stock, Shares, Issued		3,054,318
Common stock, shares, outstanding		3,054,318
Common Class A [Member]
Common Stock, Par or Stated Value Per Share	$ 0.001
Common Stock, Shares Authorized	3,750,000,000
Common Stock, Shares, Issued	155,022,167
Common stock, shares, outstanding	155,022,167
Common Class B [Member]
Common Stock, Par or Stated Value Per Share	$ 0.001
Common Stock, Shares Authorized	50,000,000
Common Stock, Shares, Issued	37,856,095
Common stock, shares, outstanding	37,856,095

Condensed Unaudited Consolida_3

Condensed Unaudited Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Revenues	$ 115,133	$ 95,284	$ 323,492	$ 253,674
Operating expenses:
Cost of revenues (excluding depreciation and amortization)	44,525	40,705	125,709	100,530
General and administrative expenses	50,643	17,150	135,682	53,270
Selling and marketing expenses	60,537	18,269	163,952	54,359
Research and development expenses	13,998	6,905	50,285	23,789
Depreciation and amortization	11,783	10,133	33,135	30,171
Acquisition related expenses	480	1,230	1,516	4,321
Restructuring expenses	30	259	467	1,950
Total operating expenses	181,996	94,651	510,746	268,390
Loss from operations	(66,863)	633	(187,254)	(14,716)
Interest expense	1,342	3,823	5,705	12,548
Other (incomes) / expenses, net	496	(188)	1,031	(546)
Gain on extinguishment of debt	0		(10,000)
Change in fair value of warrants and derivative liabilities	0	9,700	5,000	16,400
Total other (incomes) / expenses	1,838	13,335	1,736	28,402
Loss before income taxes	(68,701)	(12,702)	(188,990)	(43,118)
Income tax provision / (benefit)	428	301	(565)	1,319
Net loss	(69,129)	(13,003)	(188,425)	(44,437)
Other comprehensive (loss) / income :
Foreign currency translation adjustment	(77)	272	(152)	(516)
Total comprehensive loss	(69,206)	(12,731)	(188,577)	(44,953)
Net loss per share
Net loss	(69,129)	(13,003)	(188,425)	(44,437)
Cumulative redeemable convertible preferred stock dividends	0	3,774	7,060	11,150
Net loss available to common stockholders	$ (69,129)	$ (16,777)	$ (195,485)	$ (55,587)
Basic loss per share	$ (0.53)	$ (0.51)	$ (2.60)	$ (1.70)
Diluted loss per share	$ (0.53)	$ (0.51)	$ (2.60)	$ (1.70)
Weighted average number of shares used to compute net loss per share
Basic	129,731,980	32,607,357	75,313,520	32,607,373
Diluted	129,731,980	32,607,357	75,313,520	32,607,373

Condensed Unaudited Consolida_4

Condensed Unaudited Consolidated Statements of Operations and Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Payment Arrangement, Expense	$ 69,343	$ 26	$ 188,613	$ 79
Cost of revenues (excluding depreciation and amortization) [Member]
Share-based Payment Arrangement, Expense	1,183		1,449
General and administrative expenses [Member]
Share-based Payment Arrangement, Expense	28,243	$ 26	70,868	$ 79
Selling and marketing expenses [Member]
Share-based Payment Arrangement, Expense	35,114		94,626
Research and development expenses [Member]
Share-based Payment Arrangement, Expense	$ 4,803		$ 21,670

Condensed Unaudited Consolida_5

Condensed Unaudited Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity / (Deficit) - USD ($) $ in Thousands	Total	Treasury Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Redeemable Convertible Preferred Stock	Series A Common Stock [Member]	Series B common stock [Member]	Class A Common Stock [Member]	Class B Common Stock [Member]
Balance at Dec. 31, 2019	$ (186,334)	$ (23,469)	$ 27,909	$ (189,029)	$ (1,847)	$ 154,210	$ 99	$ 3
Balance (in shares) at Dec. 31, 2019		(8,195,464)				39,223,194	99,339,942	3,054,318
Restricted stock grants			(4)				$ 4
Restricted stock grants (in shares)							3,975,634
Restricted stock forfeitures			1				$ (1)
Restricted stock forfeitures (in shares)							(997,094)
Foreign currency translation adjustment	(741)				(741)
Net loss	(16,380)			(16,380)
Stock-based compensation	26		26
Shares issued in connection with an agreement	423		423
Shares issued in connection with an agreement (in shares)							154,560
Balance (in shares) at Mar. 31, 2020		(8,195,464)				39,223,194	102,473,042	3,054,318
Balance at Mar. 31, 2020	(203,006)	$ (23,469)	28,355	(205,409)	(2,588)	$ 154,210	$ 102	$ 3
Balance at Dec. 31, 2019	(186,334)	$ (23,469)	27,909	(189,029)	(1,847)	$ 154,210	$ 99	$ 3
Balance (in shares) at Dec. 31, 2019		(8,195,464)				39,223,194	99,339,942	3,054,318
Foreign currency translation adjustment	(516)
Net loss	(44,437)
Balance (in shares) at Sep. 30, 2020		(8,195,464)				39,223,194	111,500,433	3,054,318
Balance at Sep. 30, 2020	(230,785)	$ (23,469)	28,398	(233,466)	(2,363)	$ 154,210	$ 112	$ 3
Balance at Mar. 31, 2020	(203,006)	$ (23,469)	28,355	(205,409)	(2,588)	$ 154,210	$ 102	$ 3
Balance (in shares) at Mar. 31, 2020		(8,195,464)				39,223,194	102,473,042	3,054,318
Restricted stock grants			(1)				$ 1
Restricted stock grants (in shares)							1,148,962
Restricted stock forfeitures (in shares)							(383,695)
Foreign currency translation adjustment	(47)				(47)
Net loss	(15,054)			(15,054)
Stock-based compensation	27		27
Balance (in shares) at Jun. 30, 2020		(8,195,464)				39,223,194	103,238,309	3,054,318
Balance at Jun. 30, 2020	(218,080)	$ (23,469)	28,381	(220,463)	(2,635)	$ 154,210	$ 103	$ 3
Restricted stock grants			(9)				$ 9
Restricted stock grants (in shares)							8,743,780
Restricted stock forfeitures (in shares)							(481,656)
Foreign currency translation adjustment	272				272
Net loss	(13,003)			(13,003)
Stock-based compensation	26		26
Balance (in shares) at Sep. 30, 2020		(8,195,464)				39,223,194	111,500,433	3,054,318
Balance at Sep. 30, 2020	(230,785)	$ (23,469)	28,398	(233,466)	(2,363)	$ 154,210	$ 112	$ 3
Balance at Dec. 31, 2020	(239,220)	$ (23,469)	28,425	(242,254)	(2,037)	$ 154,210	$ 112	$ 3
Balance (in shares) at Dec. 31, 2020		(8,195,464)				39,223,194	112,012,693	3,054,318
Shares issued in connection with an acquisition	5,454		5,453				$ 1
Shares issued in connection with an acquisition (in shares)							613,497
Restricted stock grants			(4)				$ 4
Restricted stock grants (in shares)							3,687,431
Restricted stock forfeitures			2				$ (2)
Restricted stock forfeitures (in shares)							(1,629,369)
Restricted stock cancelation			18				$ (18)
Restricted stock cancelation (in shares)							(17,853,416)
Foreign currency translation adjustment	54				54
Net loss	(24,374)			(24,374)
Balance (in shares) at Mar. 31, 2021		(8,195,464)				39,223,194	96,830,836	3,054,318
Balance at Mar. 31, 2021	(258,086)	$ (23,469)	33,894	(266,628)	(1,983)	$ 154,210	$ 97	$ 3
Balance at Dec. 31, 2020	(239,220)	$ (23,469)	28,425	(242,254)	(2,037)	$ 154,210	$ 112	$ 3
Balance (in shares) at Dec. 31, 2020		(8,195,464)				39,223,194	112,012,693	3,054,318
Foreign currency translation adjustment	(152)
Net loss	(188,425)
Shares repurchased (in shares)										(2,307,692)
Balance (in shares) at Sep. 30, 2021		(8,195,464)							155,022,167	37,856,095
Balance at Sep. 30, 2021	55,785	$ (23,469)	511,929	(430,679)	(2,189)				$ 155	$ 38
Balance at Mar. 31, 2021	(258,086)	$ (23,469)	33,894	(266,628)	(1,983)	$ 154,210	$ 97	$ 3
Balance (in shares) at Mar. 31, 2021		(8,195,464)				39,223,194	96,830,836	3,054,318
Restricted stock grants			(2)						$ 1	$ 1
Restricted stock grants (in shares)									1,155,598	700,000
Restricted stock forfeitures			2						$ (2)
Restricted stock forfeitures (in shares)									(2,334,753)
Foreign currency translation adjustment	(129)				(129)
Net loss	(94,922)			(94,922)
Conversion of Series A and Series B common shares into Class A and Class B common shares, respectively			1				$ (97)	$ (3)	$ 60	$ 39
Conversion of Series A and Series B common shares into Class A and Class B common shares, respectively (in shares)							(96,830,836)	(3,054,318)	60,421,367	39,463,787
Warrants exercised	24,140		24,132						$ 8
Warrants exercised (in shares)									8,360,331
Conversion of redeemable convertible preferred stock to Class A Common Stock	193,210		193,136			$ (154,210)			$ 74
Conversion of redeemable convertible preferred stock to Class A Common Stock (in shares)						(39,223,194)			73,813,713
Shares issued in connection with the Initial Public Offering	147,739		147,724						$ 15
Shares issued in connection with the Initial Public Offering (in shares)									14,773,939
Equity issuance cost	(21,201)		(21,201)
Shares repurchased	(64,468)		(64,462)						$ (4)	$ (2)
Shares repurchased (in shares)									(4,138,866)	(2,307,692)
Restricted stock units vesting (in shares)									219,072
Stock-based compensation	126,775		126,775
Balance (in shares) at Jun. 30, 2021		(8,195,464)							152,270,401	37,856,095
Balance at Jun. 30, 2021	53,058	$ (23,469)	439,999	(361,550)	(2,112)				$ 152	$ 38
Restricted stock grants			(3)						$ 3	$ 0
Restricted stock grants (in shares)									3,281,016	0
Restricted stock forfeitures			0						$ 0
Restricted stock forfeitures (in shares)									(718,056)
Foreign currency translation adjustment	(77)				(77)
Net loss	(69,129)			(69,129)
Shares repurchased	0		0						$ 0	$ 0
Shares repurchased (in shares)									(37,679)	0
Stock-based compensation	70,668		70,668
Shares issued in connection with settlement of a dispute	1,196		1,196
Shares issued in connection with settlement of a dispute (in shares)									200,000
Options exercised	69		69
Options exercised (in shares)									26,485
Balance (in shares) at Sep. 30, 2021		(8,195,464)							155,022,167	37,856,095
Balance at Sep. 30, 2021	$ 55,785	$ (23,469)	$ 511,929	$ (430,679)	$ (2,189)				$ 155	$ 38

Condensed Unaudited Consolida_6

Condensed Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net loss	$ (188,425)	$ (44,437)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	33,135	30,171
Stock-based compensation	188,613	79
Deferred income taxes	(1,635)	(170)
Change in fair value of warrant and derivative liabilities	5,000	16,400
Gain on extinguishment of debt	(10,000)
Others, net	2,509	2,880
Changes in non-cash working capital (net of acquisitions):
Account receivable	7,423	28,967
Prepaid expenses	(1,917)	(450)
Other current assets	4,316	349
Other non-current assets	(542)	1,294
Deferred revenue	(1,314)	184
Accounts payable	(17,961)	(325)
Accrued expenses and other current liabilities	2,762	(19,405)
Other non-current liabilities	1,402	1,105
Net cash provided by operating activities	23,366	16,642
Cash flows from investing activities:
Capital expenditures	(6,883)	(1,903)
Website and software development costs	(13,421)	(17,505)
Business and asset acquisitions, net of cash acquired	(2,159)
Net cash used for investing activities	(22,463)	(19,408)
Cash flows from financing activities:
Proceeds from initial public offering, net of issuance costs	126,538
Cash paid for acquisition related liabilities	(64)	(496)
Proceeds from term loan, net of issuance cost	183,311
Proceeds from paycheck protection program loan		10,000
Repurchase of restricted stock	(64,468)
Exercise of warrants and options	110
Repayments against the credit facilities	(180,745)	(3,500)
Net cash provided by financing activities	64,682	6,004
Effect of exchange rate changes on cash and cash equivalents	(130)	(102)
Net increase in cash and cash equivalents	65,455	3,136
Cash and cash equivalents, beginning of period	50,725	37,818
Cash and cash equivalents, end of period	116,180	40,954
Supplemental cash flow disclosures including non-cash activities:
Cash paid for interest	5,673	10,330
Cash paid for income taxes, net	1,294	1,224
Contingent consideration liability established in connection with acquisitions	1,795
Shares issued in connection with acquisitions and other agreements	6,650	423
Dividends on redeemable convertible preferred stock settled in Company's equity	60,082
Non-cash settlement of warrants and derivative liabilities	63,100
Capitalized stock-based compensation as website and software development costs	8,830
Non-cash consideration for website and software development costs	$ 45	$ 770

Organization and Background

Organization and Background	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Background	1. Organization and Background (a) Nature of Business Zeta Global Holdings Corp., a Delaware Corporation (“Zeta Global Holdings”), and Zeta Global Corp., the operating company of Zeta Global Holdings and a Delaware Corporation (“Zeta” individually, or collectively with Zeta Global Holdings and its consolidated entities, as context dictates, the “Company”), is a marketing technology company that combines proprietary data, artificial intelligence and software to create a technology platform that enables marketers to acquire, retain and grow customer relationships. The Company’s technology platform powers data-driven marketing programs for enterprises across a wide range of industries and utilizes all digital distribution channels including email, search, social, mobile, display and connected TV (“CTV”). Zeta was incorporated and began operations in October 2007. (b) Initial Public Offering (“IPO”) On June 9, 2021, the Company’s registration statement on Form S-1 Co-Founder, (c) Reorganization Transactions In connection with the IPO, the Company completed the following transactions (“Reorganization Transactions”): • As per the amended and restated certificate of incorporation, the authorized capital stock consists of 3,750,000,000 shares of Class A common stock, par value $0.001 per share, 50,000,000 shares of Class B common stock, par value $0.001 per share, and 200,000,000 shares of preferred stock, par value $0.001 per share. The number of shares outstanding as of June 14, 2021 was 152,270,401 shares of Class A common stock and 37,856,095 shares of Class B common stock, based on stock outstanding as of March 31, 2021, after giving effect to: • the conversion of 39,223,194 outstanding shares, and unpaid dividends on such outstanding shares, of its Series A preferred stock, Series B-1 B-2 E-1 F-1 F-2 F-3 F-4 • 8,360,331 shares of its Class A common stock issued in connection with the exercise of outstanding warrants (the “Warrant Exercise”); • the reclassification of 3,054,318 shares of its existing Series B common stock and 26,722,208 shares of Series A common stock into shares of Class A common stock and the reclassification of 70,108,628 shares of restricted Series A common stock into shares of restricted Class A common stock (of which 8,734,893 have vested in connection with the IPO and 4,138,866 shares were repurchased by the Company); • the exchange of 39,463,787 shares of Class A common stock (after giving effect to the Preferred Conversion and the Reclassification) held by the Co-Founder Co-Founder • the repurchase of an aggregate of 4,138,866 shares of restricted Class A common stock and 2,307,692 shares of Class B common stock (of which 540,000 shares are restricted Class B common stock) as a result of the Stock Repurchase and the Tax Withholding Repurchase.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	2. Basis of Presentation and Summary of Significant Accounting Policies (a) Principles of Consolidation The accompanying condensed unaudited consolidated financial statements have been prepared by the Company in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial reporting and as required by Rule 10-01 Regulation S-X. year-end The accompanying unaudited consolidated financial statements include the accounts of Zeta and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The Company’s management considers events or transactions that occur after the balance sheet date but before the financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated through the date of issuance of these financial statements (see Note 16 to the condensed unaudited consolidated financial statements below). (b) Revenue Recognition Revenue arises primarily from the Company’s technology platform via subscription fees, volume-based utilization fees and fees for professional services designed to maximize the customer usage of technology. Revenues are recognized when control of these services is transferred to the customers, in an amount that reflects the consideration that is expected to be entitled to an exchange for the services. Sales and other taxes collected by the Company in concurrence with the revenue-producing activities are excluded from revenues. Contract assets and liabilities Contract assets represent revenue recognized for contracts that have not been invoiced to customers and also certain sales commissions that are deferred and to be recognized over the expected term of contracts for which such commissions are paid. Total contract assets were $2,507 and $1,748 as of September 30, 2021 and December 31, 2020, respectively, and are included in the account receivables, net, in the condensed unaudited consolidated balance sheets. Contract liabilities consists of deferred revenues that represent amounts billed to the customers in excess of the revenue recognized. Deferred revenues are subsequently recorded as revenues when earned in accordance with the Company’s revenue recognition policies. During the nine months ended September 30, 2021 and 2020, the Company billed and collected $34,175 and $20,760 in advance, respectively and recognized $35,489 and $20,576, respectively as revenues. As of September 30, 2021 and December 31, 2020, the deferred revenues are $2,739 and $4,053, respectively. Remaining Performance Obligations Transaction price allocated to the remaining performance obligations represents contracted revenues that have not yet been recognized, which includes unearned revenues and unbilled amounts that will be recognized as revenues in future periods. Transaction price allocated to the remaining performance obligations is influenced by several factors, including seasonality, the timing of renewals, average contract terms and foreign currency exchange rates. Unbilled portions of the remaining performance obligations are subject to future economic risks including bankruptcies, regulatory changes and other market factors. The Company excludes amounts related to performance obligations that are billed and recognized as the services are provided. This primarily consists of professional services contracts that are on a time-and-materials Disaggregation of revenues from contract with customers The Company reports disaggregation of revenues based on primary geographical markets and delivery channels / platforms. Revenues by delivery channels / platforms are based on whether the customer requirements necessitate integration with platforms or delivery channels not owned by the Company. When the Company generates revenues entirely through the Company platform, the Company considers it to be direct platform revenues. When the Company generates revenue by leveraging its platform’s integration with third parties, it is considered integrated platform revenues. The following table summarizes disaggregation for the three and nine months ended September 30, 2021, and September 30, 2020. Three Nine 2021 2020 2021 2020 Direct platform revenues $ 84,663 $ 63,346 $ 242,219 $ 180,589 Integrated platform revenues 30,470 31,938 81,273 73,085 Total revenues $ 115,133 $ 95,284 $ 323,492 $ 253,674 Refer to the Company’s accounting policy on “Segments” below for more information about disaggregation based on primary geographical markets. (c) Stock-based compensation and other stock-based payments: The measurement of share-based compensation expense for all stock-based payment awards, including restricted shares and stock options granted to the employee, consultants or advisors and non-employee The Company accounts for all stock options and restricted shares granted prior to the IPO using a fair value-based method. The fair value of each stock option granted to employees is estimated on the date of the grant using the Black-Scholes-Merton option pricing model, and the related stock-based compensation expense is recognized over the expected life of the option. The fair value of the restricted shares granted post-IPO Since the Company’s restricted stock and restricted stock units had both a performance condition (i.e. initial public offering) and a service condition, the Company uses the graded vesting attribution method to amortize the stock-based compensation. (d) Segments The Company operates as one operating segment. Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the Chief Operating Decision Maker (“CODM”) in deciding how to allocate resources and in assessing performance. The Company’s CODM is the Chief Executive Officer. Since it operates as one operating segment, all required financial segment information can be found in the condensed unaudited consolidated financial statements. Revenues and long-lived assets by geographic region are based on the physical location of the customers being served or the assets and are as follows: Revenues by geographical region consisted of the following; Three months ended September 30 Nine months ended September 30 2021 2020 2021 2020 US $ 108,034 $ 88,014 $ 301,548 $ 234,565 International 7,099 7,270 21,944 19,109 Total revenues $ 115,133 $ 95,284 $ 323,492 $ 253,674 Total long-lived assets by geographical region consisted of the following; As of September 30, 2021 December 31, 2020 US $ 43,734 $ 38,413 International 612 595 Total long-lived assets $ 44,346 $ 39,008 (e) Concentration of Credit Risk No customer accounted for more than 10% of the Company’s total revenues during the period ended September 30, 2021 and year ended December 31, 2020. Financial instruments that potentially subject the Company to concentration risk consist primarily of accounts receivable from customers. As of September 30, 2021 , there was no customer that represented more than 10% of accounts receivables balance as of that date. As of , represented

Intangible Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2021
Intangible Assets Disclosure [Abstract]
Intangible Assets	3. Intangible Assets The details of intangible assets and related accumulated amortization are set forth below: As of September 30, 2021 As of December 31, 2020 Gross Accumulated Net Gross Accumulated Net Publisher and data supply relationships $ 7,500 $ 1,146 $ 6,354 $ — $ — $ — Tradenames 2,720 2,040 680 2,720 1,634 1,086 Completed technologies 20,292 16,352 3,940 20,292 13,037 7,255 Customer relationships 52,159 34,201 17,958 45,239 24,989 20,250 Total intangible assets $ 82,671 $ 53,739 $ 28,932 $ 68,251 $ 39,660 $ 28,591 Amortization expense was $5,051 and $14,079 for the three and nine months ended September 30, 2021, respectively, and $3,913 and $11,754 for the three and nine months ended September 30, 2020, respectively. Weighted average useful life of the unamortized intangibles as of September 30, 2021 was 2.10 years. Based on the amount of intangible assets subject to amortization, as of September 30, 2021, the Company’s estimated future a m Total estimated future amortization expense is as follows: As of September 30, 2021 Year ended December 31, Remaining three months of 2021 $ 4,952 2022 15,332 2023 6,040 2024 2,002 2025 482 2026 and thereafter 124 Total $ 28,932

Goodwill

Goodwill	9 Months Ended
	Sep. 30, 2021
Goodwill Disclosure [Abstract]
Goodwill	4. Goodwill The following is a summary of the carrying value of goodwill: Balance as of January 1, 2021 $ 76,432 Acquisition of Vital 3,910 Acquisition of Kinetic 1,578 Foreign currency translation (3 ) Balance as of September 30, 2021 $ 81,917 There were no events during the three months ended September 30, 2021 to which an impairment analysis would be warranted.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2021
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	5. Acquisitions The Company’s acquisitions have been accounted for under the purchase method of accounting. The total purchase price of each acquisition was allocated to the fair value of assets acquired and liabilities assumed based on their fair values at the acquisition date, with any excess recorded as goodwill. The Company agreed to pay a portion of the purchase price for certain acquisitions in the form of contingent purchase price and the unpaid amounts of these liabilities are included in the acquisition related liabilities on the condensed unaudited consolidated balance sheets as of September 30, 2021 and December 31, 2020. On March 1, 2021, the Company entered into a merger agreement with the sellers of Kinetic Data Solutions, LLC (“Kinetic”), an entity controlled by the Chief Executive Officer of the Company, to purchase all of the issued and outstanding stock of Kinetic. The fair value of the purchase consideration was estimated at $2,762. The Company agreed to issue 306,749 shares of Series A common stock with a fair value of $2,738 and certain earn-outs based on the operating performance of the acquired business after the closing date. The earn-out earn-out On March 3, 2021, the Company entered into a stock purchase agreement with the sellers of Vital Digital, Corp (“Vital”) to purchase all of the issued and outstanding shares of common stock of Vital. The fair value of the purchase consideration for this transaction is determined as $7,894, with $3,400 in cash, 306,748 shares of Series A common stock with a fair value of $2,710, $1,206 in earnouts based on the operating performance of the acquired business after the closing date, and $578 in cash holdback. The Company has recorded this transaction based on the preliminary purchase price allocation. Accordingly, the Company has recognized $5,320 as customer relationship intangibles, $3,910 as goodwill, $1,385 as deferred tax liability and $49 as other net assets associated with this acquisition. Caivis, one of the Company’s related parties, owned 5% interest in Vital as of the effective date of this stock purchase agreement (refer to Note 13 for a description of relationship with Caivis). The revenues and earnings from these acquisitions are not significant to the Company’s condensed unaudited consolidated financial statements for the three months and nine months ending September 30, 2021. Goodwill acquired by the Company in these acquisitions is not deductible for tax purposes. The pro forma results of the Company as if these acquisitions had taken place on the first day of 2020 were not materially different from the amounts reflected in the accompanying condensed unaudited consolidated financial statements. The Company has recorded the earn-outs related to these acquisitions based on the fair value determined on the date of the acquisition, however the Company believes that the actual payouts for these acquisitions could be different from such recorded fair values.

Acquisition Related Liabilities

Acquisition Related Liabilities	9 Months Ended
	Sep. 30, 2021
Acquisition Related Liabilities [Abstract]
Acquisition Related Liabilities Disclosure [Text Block]	6. Acquisition Related Liabilities The following is a summary of acquisition related liabilities: eBay CRM Sizmek PlaceIQ Ignition One Kinetic Vital Total Balance as of January 1, 2021 $ 17,137 $ 4,402 $ 256 $ 1,360 $ — $ — $ 23,155 Additions — — — — 24 1,784 1,808 Payments made during the year — — (64 ) — — — (64 ) Change in fair value of earn-out 649 (470 ) (192 ) — — — (13 ) Balance as of September 30, 2021 $ 17,786 $ 3,932 $ — $ 1,360 $ 24 $ 1,784 $ 24,886 The changes in the fair value of the acquisition related liabilities are included in other expenses / (income) on the condensed unaudited consolidated statements of operations and comprehensive loss. The Company is a party to a litigation matter in relation to certain acquisition related liabilities for its eBay CRM acquisition dated November 2, 2015. The amounts payable for eBay CRM has been contested by the Company in the court of law. On October 14, 2021, the Company paid a portion of the liability for $9,786 to the sellers of eBay CRM business in satisfaction of a judgment, which was being accrued at $9,137. As such, the Company accrued an additional amount of $649 during the three months ending on September 30, 2021 such that the Company has full accrual for the payment relating to this liability as of September 30, 2021. Further, the Company has provided a letter of credit amounting to $6,028, against these payable amounts, which is in the process of being

Credit Facilities

Credit Facilities	9 Months Ended
	Sep. 30, 2021
Line of Credit Facility [Abstract]
Credit Facilities	7. Credit Facilities The Company’s long-term borrowings are as follows: As of September 30, 2021 As of December 31, 2020 Credit facility $ 185,000 $ 137,950 Loan under paycheck protection program — 10,000 Revolving loan — 42,600 Total borrowings 185,000 190,550 Less: Unamortized discount on debt — (426 ) Unamortized deferred financing cost (1,472 ) (431 ) Long-term borrowings $ 183,528 $ 189,693 In July 2016, the Company entered into a revolving credit, guarantee and security agreement with a financial institution and subsequently amended the agreement in May 2017. The agreement provides for a maximum revolving advance amount of $50,000. Interest on the outstanding balance is charged at an annual rate of the financial institution’s Prime Lending Rate (“PLR”)+ 1.25 2.25 In July 2015, the Company entered into a term loan facility with a financial institution that was also invested in the Company’s Series E-1 LIBOR+7.5 On February 3, 2021, the Company entered into a $ Senior Secured Credit Facility (“Senior Secured Credit Facility”) with a syndicate of financial institutions and institutional lenders led by BofA Securities, Inc., as a lead arranger and sole bookrunner, and Bank of America, N.A., as sole administrative agent. The Senior Secured Credit Facility is for up to $222,500, which consists of (i) a $73,750 initial Revolving Facility that was drawn at closing date, (ii) a $111,250 Term Facility that was drawn at closing date, and (iii) a $37,500 in incremental Revolving Facility commitment that remains undrawn. In addition, the Company has an outstanding letter of credit amounting to $7,272 against the available revolving credit facility, of which a letter of credit amounting to $6,028 against the amount payable to eBay is in the process of being assets. Interest on the current outstanding balances is payable quarterly and calculated using a LIBOR rate of no lower than LIBOR+2.125% and no higher than LIBOR+2.625% based on the Company’s consolidated net leverage ratio stated in the credit agr e The Senior Secured Credit Facility contains certain financial maintenance covenants including consolidated net leverage ratio and consolidated fixed charge coverage ratio. In addition, this agreement contains restrictive covenants that may limit the Company’s ability to, among other things, acquire equity interest of the Company from its shareholders, repurchase / retire any of the Company’s securities, and pay dividends or distribute excess cash flow. Additionally, the Company is required to submit periodic financial covenant letters that would include current net leverage ratio and fixed charge coverage ratio, among others. As of September 30, 2021, applicable total leverage ratio and fixed charge coverage ratio was 4.0 and 1.25, respectively and the Company was in compliance with these covenants. Since the time lag between the effective date of the new credit facility and September 30, 2021 is minimal and the interest rates on the Company’s new credit facility approximates the current market rates, the fair value of the debt is approximately equal to the carrying amount as of September 30, 2021. On April 23, 2020, the Company received proceeds from a loan April 24, 2022 As of September 30, 2021 Year Ended December 31, Remaining three months of 2021 $ — 2022 5,625 2023 11,250 2024 11,250 2025 16,875 2026 and thereafter 140,000 Total* $ 185,000 *Includes $4,219 repayable against the term loan facility within the

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. Commitments and Contingencies (a) Purchase obligations The Company entered into non-cancellable As of September 30, 2021 Year Ended December 31, Remaining three months of 2021 $ 2,468 2022 9,785 2023 5,700 2024 5,700 2025 5,700 2026 and thereafter 1,425 Total $ 30,778 (b) Lease commitments The Company maintains leased offices in the United States of America, United Kingdom, India and France. Deferred rent as of September 30, 2021 and December 31, 2020 was $2,458 and $2,652, respectively for these leases and is included in other current liabilities and non-current As of September 30, 2021 Year Ended December 31, Remaining three months of 2021 $ 778 2022 2,553 2023 2,133 2024 1,953 2025 1,788 2026 and thereafter 5,062 Total $ 14,267 The Company is a party to various litigations and administrative proceedings related to claims arising from its operations in the ordinary course of business including in relation to certain contingent purchase price obligations noted above. The Company records provisions for losses when claims become probable, and the amounts are estimable. Although the outcome of these matters cannot be predicted with certainty, the Company’s management believes that the resolution of the matters will not have a material impact on the Company’s business, results of operations, financial condition, or cash flows.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	9. Stock-Based Compensation Stock-based compensation plan In 2008, the Company adopted its 2008 Stock Option/Stock Issuance Plan, and, in 2017, adopted the Zeta Global Holdings Corp. 2017 Incentive Plan (collectively, the “Plans”). The Plans permit the issuance of stock options, restricted stock and restricted stock units to employees, directors, and officers, consultants or advisors and non-employee five In the past, the Company has cancelled certain restricted stock and in lieu of such cancellation has issued restricted stock units to the holders of that restricted stock, with the same vesting conditions as restricted stock. Restricted Stock and Restricted Stock Units As noted above, the Company’s restricted stock and restricted stock units did not vest until the change of control. On March 24, 2021, the Company’s board of directors approved a modification in the vesting terms of its restricted stock and restricted stock unit awards. Pursuant to that approval, the existing restricted stock and restricted stock units were divided into three broad categories with different vesting conditions as follows: a) For the first category of holders, terms of the modification provide the holders an option to tender up to 20% of their outstanding awards to the Company in a buy-back one b) For the second category of holders, terms of the modification provide for vesting upon the effective date of the IPO as follows: (i) 25% of shares with an original grant date of less than five years prior to the IPO and (ii) 100% of shares with a grant date of five years or older. Post the IPO, additional vesting is deferred for one year. Thereafter the rema i c) For the third category of holders, terms of the modification provide for vesting to begin at the end of the first quarter following the one fifth The revised terms were communicated to the restricted stock and restricted stock unit holders. The above modification was accounted for under the guidance in ASC 718-20-35-3. improbable-to-improbable 718-20-55-118 The restricted stock or restricted stock units that are tendered by the holders in the buy-back The following is the activity of restricted stock and restricted stock units granted by the Company: Shares Weighted Average Non-vested 85,903,970 $ 2.80 Granted (1) 9,112,569 8.62 Vested (9,300,893 ) 11.04 Forfeited (2) (4,700,102 ) 9.46 Cancelled (3) (16,655,197 ) 3.60 Modified (68,986,297 ) 2.78 Modified and reissued 68,986,297 11.36 Non-vested , 2021 64,360,347 $ 10.94 (1) During the nine months ended September 30, 2021, the Company granted 8,824,045 restricted stock and 288,724 restricted stock units to its employees and board members, of which 1,660,677 restricted stock and 98,993 restricted stock units were granted prior to March 12, 2021 and will be governed by the vesting rules described in a), b) and c) above. Remaining shares that were granted on or after March 12, 2021 shall vest over a period of four years, with 25% vesting on the one-year (2) During the nine months ended September 30, 2021, the 4,682,178 restricted stock and 17,924 restricted stock units were forfeited. (3) During the nine months ended September 30, 2021, the Company also cancelled 16,655,197 shares of restricted stock granted to holders of series A redeemable convertible preferred shares (see Note 10 to the condensed unaudited consolidated financial statements below). Performance Stock Unit (“PSU”) Award On August 18, 2021, the Compensation Committee of the Board of Directors approved 1,500,000 PSU awards under the Company’s 2021 Incentive Award Plan. Upon achievement of the conditions described below, the PSUs could result in the issuance of up to 3,000,000 shares of Class A common stock. Each PSU represents the right to receive shares of Class A common stock as set forth in the PSU grant agreement or, at the option of the Company, an equivalent amount of cash. Participants have no right to the distribution of any shares or payment of any cash until the time (if ever) the PSUs are earned and have vested. Each PSU provides for the right to receive a dividend equivalent to the value of any ordinary cash dividends paid on substantially all the outstanding shares of Class A common stock if the PSUs are earned and vested. 20 Day VWAP of Class A common stock Below $10 $10.00 $12.50 $15.00 $18.50 $22.00 Percentage of target PSUs 0% 25% 50% 100% 150% 200% Upon being earned and subject to the participant’s continued service, PSUs will vest in three equal annual installments, with the first installment vesting on the date of determination for the applicable quarter for which such PSUs were earned, and the second and third installments vesting on the second and third anniversaries of such quarterly determination date, subject to accelerated vesting in connection with a change in control. In the event of Participant’s termination of service for any reason, all unvested PSUs will immediately and automatically be cancelled and forfeited, except, to the extent a Participant is terminated without cause or resigns for good reason, (i) any PSUs earned for any quarter prior to the date of termination will fully vest, and (ii) any PSUs earned in the quarter in which the termination date occurs will fully vest. The Company engaged a third-party valuation firm to determine the estimated fair value of the PSUs using the Monte Carlo simulation method, which was determined as $1.95 per PSU. During the three and nine months ended September 30, 2021, the Company recognized an expense of $86 related to target PSUs during such period. 2021 Employee Stock Purchase Plan (“ESPP”) In connection with its IPO, the Company adopted the 2021 Employee Stock Purchase Plan, or the 2021 ESPP. The Company expects that all of its employees will be eligible to participate (the “participants”) in the 2021 ESPP. The 2021 ESPP permits participants to purchase the Company’s Class A common stock through contributions up to a specified percentage of their eligible compensation. The maximum number of shares that may be purchased by a participant during any offering period are capped at 10,000. In addition, no employee will be permitted to accrue the right to purchase shares under the Section 423 component at a rate in excess of $25,000 worth of shares during any calendar year during which such a purchase right is outstanding (based on the fair market value per share of our Class A common stock as of the first day of the offering period). On July 28, 2021, the Compensation Committee of the Board of Directors approved the Company’s first offering period under the 2021 ESPP, which commenced on August 1, 2021 and will end on November 30, 2021. Following the end of the first offering period, the 2021 ESPP shall have consecutive offering periods of approximately six months in length commencing each year on December 1 and June 1 and ending on each May 31 and November 30 occurring six months later, as applicable. During the three months and nine months ended September 30, 2021, the Company recognized an expense of $180 at fair value of $2.16 per 2021 ESPP share, related to the enrollments under the first offering period that commenced on August 1, 2021. The fair value of the 2021 ESPP was determined, based on the Monte Carlo simulation method, by a third party valuation firm engaged by the Company. Unrecognized compensation expense The Company has $607,110 of unrecognized compensation expense related to its 64,360,347 unvested restricted stock and restricted stock units, 1,500,000 performance stock units and common stock to be issued under the ESPP. This unrecognized stock-based compensation will be recognized over a weighted average period of 1.37 years.

Stockholders' Equity _ (Deficit

Stockholders' Equity / (Deficit)	9 Months Ended
	Sep. 30, 2021
Stockholders' Equity Note [Abstract]
Stockholders' Equity / (Deficit)	10. Stockholders’ Equity / (Deficit) On February 24, 2021, the Company’s Board of Directors approved the correction of the conversion price of Series A redeemable convertible preferred shares held by certain shareholders and cancelation of 16,655,197 shares of restricted stock granted to these holders of Series A redeemable convertible preferred shares. The Board of Directors determined that the restricted shares were issued to those shareholders in order to avoid dilution of their ownership in the Company as a result of other grants of shares. It was further determined that the dilutive effect of those other restricted shares should have been addressed by an adjustment to the conversion price of the Series A redeemable convertible preferred shares. Therefore, the issuance of the restricted shares to these holders of the Series A redeemable convertible preferred shares was determined to be an error and were duplicative with the corrected calculation of the conversion price of Series A redeemable convertible preferred shares. The conversion price of these Series A redeemable convertible preferred stock was adjusted to $0.073587 from $0.59. The number of shares outstanding as of June 14, 2021 was 152,270,401 shares of our Class A common stock and 37,856,095 shares of our Class B common stock, based on stock outstanding as of March 31, 2021, after giving effect to each of the Reorganization Transactions described in Note 1, as a result of the Company’s IPO. Rights of Class A and Class B common stockholders: The Company’s amended and restated Certificate of Incorporation defines the rights of the different classes of common stock as under: • Equal Status- Except as otherwise provided in the Certificate of Incorporation or required by applicable l a • Voting- Except as otherwise required by applicable law, at all meetings of stockholders and on all matters submitted to a vote of stockholders of the Company generally, each holder of Class A common stock, as such, shall have the right to one (1) vote per share of Class A common stock held of record by such holder and each holder of Class B common stock, as such, shall have the right to ten (10) votes per share of Class B common stock held of record by such holder. • Dividend Rights- Shares of Class A common stock and Class B common stock shall be treated equally, identically and ratably, on a per share basis, with respect to any dividends as may be declared and paid from time to time by the Board of Directors of the Company. • Liquidation, Dissolution or Winding Up- Shares issued for a settlement In connection with a settlement of a dispute with a vendor, the Company issued 200,000 shares which it recorded as a General & Administrative expense in the condensed unaudited statements of operations and comprehensive loss.

Warrants and Derivative Liabili

Warrants and Derivative Liabilities	9 Months Ended
	Sep. 30, 2021
Warrants and Rights Note Disclosure [Abstract]
Warrants and Derivative Liabilities	11. Warrants and Derivative Liabilities The following assumptions were used to determine the fair value of the warrants and derivative liabilities as of September 30, 2021 and December 31, 2020: As of September 30, 2021 As of December 31, 2020 Stock price $ — $ 7.56 Exercise price $ — $ 0.01 Risk-free interest rate — 0.09% Expected volatility — 64.0% Time to maturity (in years) — 0.63 As of December 31, 2020, the fair value of the warrants and derivative liabilities was $58,100. In connection with the Company’s IPO, all the outstanding warrants were exercised by holders of those warrants and redeemable convertible preferred stock were converted to Class A common stock of the Company. The derivative liability, that represented the conversion feature of certain redeemable convertible preferred stock has been settled in the additional paid in capital. For the three months ended September 30, 2020, the Company recognized an expense of $9,700, related to the changes in the fair value of warrants and derivative liabilities. There was no such expense in the three months ended September 30, 2021 due to the extinguishment of the warrants and derivative liability in connection with the Company’s IPO during Q2 2021. For the nine months ended September 30, 2021 and 2020, the Company recognized an expense related to changes in the fair value of such warrants and derivative liabilities of $5,000 and $16,400, respectively.

Fair Value Disclosures

Fair Value Disclosures	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Disclosures	12. Fair Value Disclosures Fair value is the price that would be received from the sale of an asset or paid to transfer a liability assuming an orderly transaction in the most advantageous market at the measurement date. U.S. GAAP establishes a hierarchical disclosure framework which prioritizes and ranks the level of observability of inputs used in measuring fair value. These tiers include: Level 1 is defined as observable inputs such as quoted prices in active markets for identical assets; Level 2 is defined as observable inputs other than Level 1 prices such as quoted prices for similar assets; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and Level 3 is defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. The following table represents the fair value of the financial instruments measured at fair value on a recurring basis: As of September 30, 2021 Level 1 Level 2 Level 3 Total Assets Cash and cash equivalents* $ 5,764 $ — $ — $ 5,764 Total assets measured at fair value $ 5,764 $ — $ — $ 5,764 Liabilities Derivative liability $ — $ — $ — $ — Warrant liability — — — — Acquisition related liabilities — — 24,886 24,886 Total liabilities measured at fair value $ — $ — $ 24,886 $ 24,886 As of December 31, 2020 Assets Level 1 Level 2 Level 3 Total Cash and cash equivalents* $ 12,257 $ — $ — $ 12,257 Total assets measured at fair value $ 12,257 $ — $ — $ 12,257 Liabilities Derivative liability $ — $ — $ 38,400 $ 38,400 Warrant liability — — 19,700 19,700 Acquisition related liabilities — — 23,155 23,155 Total liabilities measured at fair value $ — $ — $ 81,255 $ * Includes cash invested by the Company in certain money market accounts with a financial institution. As noted above in Note 7, as of September 30, 2021 and December 31, 2020, the Company determined that the Term Loan is classified as Level 3 and the relevant fair values were approximately equal to the book value as of September 30, 2021 and $152,538 as of December 31, 2020. The following table reconciles the changes in the fair value of the liabilities categorized within Level 3 of the fair value hierarchy for the nine months ended September 30, 2021 and year ended December 31, 2020: Warrant Acquisition Derivative Balance as of January 1, 2021 $ 19,700 $ 23,155 $ 38,400 Additions, net of payments — 1,744 — Change in fair value 4,400 (13) 600 Extinguishment of the warrant and derivative liabilities (24,100) — (39,000) Balance as of September 30, 2021 $ — $ 24,886 $ — In connection with certain business combinations, the Company may owe additional purchase consideration (contingent consideration included in the acquisition related liabilities) based on the financial performance of the acquired entities after their acquisition. The fair value of the contingent consideration was determined using an unobservable input such as projected revenues or collections of accounts receivables. Changes in any of the assumptions related to the unobservable inputs identified above may change the contingent consideration’s fair value.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Related Party Transactions	13. Related Party Transactions Caivis Acquisition Corp. II, Caivis Acquisition Corp. IV, Caivis Investment Company V, LLC and Caivis Investment Company VI, LLC (collectively, the “Caivis Group”) are entities owned by many of the same stockholders of the Company. In addition, the Chief Executive Officer of the Company owns a controlling interest in the Caivis Group. On April 9, 2012, the Company amended its agreement with the Caivis Group, whereby the Caivis Group will provide support for general administrative and corporate development activities, including sourcing and evaluating potential partners and acquisition targets to the Company for $2,000 per year. This agreement with the Caivis Group was terminated on December 31, 2019 and therefore no such expenses are incurred during FY2020 and the nine months ended on September 30, 2021. As of December 31, 2020, the Company had outstanding payables of $533 to the Caivis Group included in the “accounts payable and accrued expenses” in the condensed unaudited consolidated balance sheets. During the nine months ended on September 30, 2021, the Company paid an amount of $533 and as such there is no outstanding payable to the Caivis Group as of September 30, 2021. Casting Made Simple Corp. (“CMS”) is an entity owned by the Caivis Group and the Chief Executive Officer’s spouse. On December 28, 2018, the Company entered into an agreement with CMS to monetize traffic generated through websites owned by CMS and give a profit share to CMS. During the three and nine months ended September 30, 2021, the Company recognized $49 and $211, respectively and during the three and nine months ended September 30, 2020, the Company recognized $92 and $277, respectively, as direct cost of revenues in the condensed unaudited consolidated statements of operations and comprehensive loss, representing the profit shared by the Company with CMS. As of September 30, 2021 and December 31, 2020, the Company had outstanding payables of $48 and $70, respectively to CMS and included in the “accounts payable and accrued expenses” in the condensed unaudited consolidated balances sheets.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	14. Income Taxes The Company’s income tax provision consists of federal, foreign, and state taxes necessary to align the Company’s year-to-date For the interim period ended September 30, 2020, the Company utilized the annual effective tax rate methodology to determine its income tax provision. For the interim period ended September 30, 2021, the Company departed from the annual effective tax rate methodology and computed its income tax provision using a discrete method. The use of the discrete method was made in accordance with authoritative accounting guidance, which allows for the use of a discrete method when there are significant changes to the projected annual effective tax rate as a result of minor adjustments to projected pre-tax For the three months ended September 30, 2021, the Company recorded an income tax provision of $428. The income tax provision related The effective tax rate for the three months ended September 30, 2021 was (0.62)% on a pre-tax pre-tax

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Common Stockholders	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net Loss Per Share Attributable to Common Stockholders	15. Net Loss Per Share Attributable to Common Stockholders Basic net loss per share is computed using the two-class The following table sets forth the calculation of basic and diluted net loss per share attributable to common stockholders during the periods presented: Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Net loss $ (69,129) $ (13,003) $ (188,425) $ (44,437) Cumulative redeemable convertible preferred stock dividends — 3,774 7,060 11,150 Numerator for Basic and Dilutive loss per share - loss available to common stockholders $ (69,129) $ (16,777) $ (195,485) $ (55,587 ) Denominator: Class A common stock 111,312,720 — 50,027,683 — Class B common stock 18,419,260 — 7,300,725 — Series A common stock — 26,108,711 14,420,964 26,108,727 Series B common stock — 3,054,318 1,664,380 3,054,318 Warrants (convertible to Series A common stock) — 3,444,328 1,899,768 3,444,328 Denominator for Basic and Dilutive loss per share-weighted-average common stock 129,731,980 32,607,357 75,313,520 32,607,373 Basic loss per share $ (0.53) $ (0.51) $ (2.60) $ (1.70) Dilutive loss per share $ (0.53) $ (0.51) $ (2.60) $ (1.70) Since the Company was in a net loss position for all periods presented, basic loss per share calculation excludes redeemable convertible preferred stock as it does not participate in net losses of the Company. Additionally, net loss per share attributable to common shareholders was the same on a basic and diluted basis, as the inclusion of all potential common equivalent shares outstanding would have been anti-dilutive. Anti-dilutive common equivalent shares were as follows: Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Options (convertible to Series A common stock) 923,750 1,137,026 923,750 1,137,026 Warrants (convertible to Series A common stock) — 1,973,763 — 1,973,763 Redeemable convertible preferred stock — 39,223,194 — 39,223,194 Restricted stock and restricted stock units 64,360,347 84,486,332 64,360,347 84,486,332 Performance stock units 1,500,000 — 1,500,000 —

Subsequent Event

Subsequent Event	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Event	16. Subsequent Event On October 1, 2021, the Company acquired the digital survey platform business of Apptness Media Group, LLC (“Seller”) lock-up Additionally, the Company may also (i) release to Selle r earn-out The Company has not completed the purchase price allocation of this acquisition prior to the issuance of these financial statements, and an estimate of the financial effect of the transaction cannot be made. All other business combination disclosures are not available due to the proximity of the acquisition to the issuance of these financial statements.

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Principles of Consolidation	(a) Principles of Consolidation The accompanying condensed unaudited consolidated financial statements have been prepared by the Company in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial reporting and as required by Rule 10-01 Regulation S-X. year-end The accompanying unaudited consolidated financial statements include the accounts of Zeta and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The Company’s management considers events or transactions that occur after the balance sheet date but before the financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated through the date of issuance of these financial statements (see Note 16 to the condensed unaudited consolidated financial statements below).
Revenue Recognition	(b) Revenue Recognition Revenue arises primarily from the Company’s technology platform via subscription fees, volume-based utilization fees and fees for professional services designed to maximize the customer usage of technology. Revenues are recognized when control of these services is transferred to the customers, in an amount that reflects the consideration that is expected to be entitled to an exchange for the services. Sales and other taxes collected by the Company in concurrence with the revenue-producing activities are excluded from revenues. Contract assets and liabilities Contract assets represent revenue recognized for contracts that have not been invoiced to customers and also certain sales commissions that are deferred and to be recognized over the expected term of contracts for which such commissions are paid. Total contract assets were $2,507 and $1,748 as of September 30, 2021 and December 31, 2020, respectively, and are included in the account receivables, net, in the condensed unaudited consolidated balance sheets. Contract liabilities consists of deferred revenues that represent amounts billed to the customers in excess of the revenue recognized. Deferred revenues are subsequently recorded as revenues when earned in accordance with the Company’s revenue recognition policies. During the nine months ended September 30, 2021 and 2020, the Company billed and collected $34,175 and $20,760 in advance, respectively and recognized $35,489 and $20,576, respectively as revenues. As of September 30, 2021 and December 31, 2020, the deferred revenues are $2,739 and $4,053, respectively. Remaining Performance Obligations Transaction price allocated to the remaining performance obligations represents contracted revenues that have not yet been recognized, which includes unearned revenues and unbilled amounts that will be recognized as revenues in future periods. Transaction price allocated to the remaining performance obligations is influenced by several factors, including seasonality, the timing of renewals, average contract terms and foreign currency exchange rates. Unbilled portions of the remaining performance obligations are subject to future economic risks including bankruptcies, regulatory changes and other market factors. The Company excludes amounts related to performance obligations that are billed and recognized as the services are provided. This primarily consists of professional services contracts that are on a time-and-materials Disaggregation of revenues from contract with customers The Company reports disaggregation of revenues based on primary geographical markets and delivery channels / platforms. Revenues by delivery channels / platforms are based on whether the customer requirements necessitate integration with platforms or delivery channels not owned by the Company. When the Company generates revenues entirely through the Company platform, the Company considers it to be direct platform revenues. When the Company generates revenue by leveraging its platform’s integration with third parties, it is considered integrated platform revenues. The following table summarizes disaggregation for the three and nine months ended September 30, 2021, and September 30, 2020. Three Nine 2021 2020 2021 2020 Direct platform revenues $ 84,663 $ 63,346 $ 242,219 $ 180,589 Integrated platform revenues 30,470 31,938 81,273 73,085 Total revenues $ 115,133 $ 95,284 $ 323,492 $ 253,674 Refer to the Company’s accounting policy on “Segments” below for more information about disaggregation based on primary geographical markets.
Stock-based compensation and other stock-based payments:	(c) Stock-based compensation and other stock-based payments: The measurement of share-based compensation expense for all stock-based payment awards, including restricted shares and stock options granted to the employee, consultants or advisors and non-employee The Company accounts for all stock options and restricted shares granted prior to the IPO using a fair value-based method. The fair value of each stock option granted to employees is estimated on the date of the grant using the Black-Scholes-Merton option pricing model, and the related stock-based compensation expense is recognized over the expected life of the option. The fair value of the restricted shares granted post-IPO
Segments	(d) Segments The Company operates as one operating segment. Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the Chief Operating Decision Maker (“CODM”) in deciding how to allocate resources and in assessing performance. The Company’s CODM is the Chief Executive Officer. Since it operates as one operating segment, all required financial segment information can be found in the condensed unaudited consolidated financial statements. Revenues and long-lived assets by geographic region are based on the physical location of the customers being served or the assets and are as follows: Revenues by geographical region consisted of the following; Three months ended September 30 Nine months ended September 30 2021 2020 2021 2020 US $ 108,034 $ 88,014 $ 301,548 $ 234,565 International 7,099 7,270 21,944 19,109 Total revenues $ 115,133 $ 95,284 $ 323,492 $ 253,674 Total long-lived assets by geographical region consisted of the following; As of September 30, 2021 December 31, 2020 US $ 43,734 $ 38,413 International 612 595 Total long-lived assets $ 44,346 $ 39,008
Concentration of Credit Risk	(e) Concentration of Credit Risk No customer accounted for more than 10% of the Company’s total revenues during the period ended September 30, 2021 and year ended December 31, 2020. Financial instruments that potentially subject the Company to concentration risk consist primarily of accounts receivable from customers. As of September 30, 2021 , there was no customer that represented more than 10% of accounts receivables balance as of that date. As of , represented

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Disaggregation of Revenue	The following table summarizes disaggregation for the three and nine months ended September 30, 2021, and September 30, 2020. Three Nine 2021 2020 2021 2020 Direct platform revenues $ 84,663 $ 63,346 $ 242,219 $ 180,589 Integrated platform revenues 30,470 31,938 81,273 73,085 Total revenues $ 115,133 $ 95,284 $ 323,492 $ 253,674
Schedule of Revenues and Long-Lived Assets by Geographic Region are Based on the Physical Location of the Customers Being Served or the Assets	Revenues by geographical region consisted of the following; Three months ended September 30 Nine months ended September 30 2021 2020 2021 2020 US $ 108,034 $ 88,014 $ 301,548 $ 234,565 International 7,099 7,270 21,944 19,109 Total revenues $ 115,133 $ 95,284 $ 323,492 $ 253,674 Total long-lived assets by geographical region consisted of the following; As of September 30, 2021 December 31, 2020 US $ 43,734 $ 38,413 International 612 595 Total long-lived assets $ 44,346 $ 39,008

Intangible Assets (Tables)

Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2021
Intangible Assets Disclosure [Abstract]
Summary of Intangible Assets and Related Accumulated Amortization	The details of intangible assets and related accumulated amortization are set forth below: As of September 30, 2021 As of December 31, 2020 Gross Accumulated Net Gross Accumulated Net Publisher and data supply relationships $ 7,500 $ 1,146 $ 6,354 $ — $ — $ — Tradenames 2,720 2,040 680 2,720 1,634 1,086 Completed technologies 20,292 16,352 3,940 20,292 13,037 7,255 Customer relationships 52,159 34,201 17,958 45,239 24,989 20,250 Total intangible assets $ 82,671 $ 53,739 $ 28,932 $ 68,251 $ 39,660 $ 28,591
Summary of Total Estimated Future Amortization Expense	Total estimated future amortization expense is as follows: As of September 30, 2021 Year ended December 31, Remaining three months of 2021 $ 4,952 2022 15,332 2023 6,040 2024 2,002 2025 482 2026 and thereafter 124 Total $ 28,932

Goodwill (Tables)

Goodwill (Tables)	9 Months Ended
	Sep. 30, 2021
Goodwill Disclosure [Abstract]
Summary of Goodwill	The following is a summary of the carrying value of goodwill: Balance as of January 1, 2021 $ 76,432 Acquisition of Vital 3,910 Acquisition of Kinetic 1,578 Foreign currency translation (3 ) Balance as of September 30, 2021 $ 81,917

Acquisition Related Liabiliti_2

Acquisition Related Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Acquisition Related Liabilities [Abstract]
Schedule of Acquisition Related Liabilities	The following is a summary of acquisition related liabilities: eBay CRM Sizmek PlaceIQ Ignition One Kinetic Vital Total Balance as of January 1, 2021 $ 17,137 $ 4,402 $ 256 $ 1,360 $ — $ — $ 23,155 Additions — — — — 24 1,784 1,808 Payments made during the year — — (64 ) — — — (64 ) Change in fair value of earn-out 649 (470 ) (192 ) — — — (13 ) Balance as of September 30, 2021 $ 17,786 $ 3,932 $ — $ 1,360 $ 24 $ 1,784 $ 24,886

Credit Facilities (Tables)

Credit Facilities (Tables)	9 Months Ended
	Sep. 30, 2021
Line of Credit Facility [Abstract]
Schedule Of Long-Term Borrowings	The Company’s long-term borrowings are as follows: As of September 30, 2021 As of December 31, 2020 Credit facility $ 185,000 $ 137,950 Loan under paycheck protection program — 10,000 Revolving loan — 42,600 Total borrowings 185,000 190,550 Less: Unamortized discount on debt — (426 ) Unamortized deferred financing cost (1,472 ) (431 ) Long-term borrowings $ 183,528 $ 189,693
Summary of Maturities of Long-term Debt	As of September 30, 2021, the repayment schedule for the long-term borrowings was as follows: As of September 30, 2021 Year Ended December 31, Remaining three months of 2021 $ — 2022 5,625 2023 11,250 2024 11,250 2025 16,875 2026 and thereafter 140,000 Total* $ 185,000

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Schedule of Commitments For The Base Rents	Commitments for the base rents as of September 30, 2021 are as follows: As of September 30, 2021 Year Ended December 31, Remaining three months of 2021 $ 778 2022 2,553 2023 2,133 2024 1,953 2025 1,788 2026 and thereafter 5,062 Total $ 14,267
Summary of Long-term Purchase Commitment	The Company entered into non-cancellable As of September 30, 2021 Year Ended December 31, Remaining three months of 2021 $ 2,468 2022 9,785 2023 5,700 2024 5,700 2025 5,700 2026 and thereafter 1,425 Total $ 30,778

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Summary of The Activity of Restricted Stock And Restricted Stock Units Granted By The Company	The following is the activity of restricted stock and restricted stock units granted by the Company: Shares Weighted Average Non-vested 85,903,970 $ 2.80 Granted (1) 9,112,569 8.62 Vested (9,300,893 ) 11.04 Forfeited (2) (4,700,102 ) 9.46 Cancelled (3) (16,655,197 ) 3.60 Modified (68,986,297 ) 2.78 Modified and reissued 68,986,297 11.36 Non-vested , 2021 64,360,347 $ 10.94 (1) During the nine months ended September 30, 2021, the Company granted 8,824,045 restricted stock and 288,724 restricted stock units to its employees and board members, of which 1,660,677 restricted stock and 98,993 restricted stock units were granted prior to March 12, 2021 and will be governed by the vesting rules described in a), b) and c) above. Remaining shares that were granted on or after March 12, 2021 shall vest over a period of four years, with 25% vesting on the one-year (2) During the nine months ended September 30, 2021, the 4,682,178 restricted stock and 17,924 restricted stock units were forfeited. (3) During the nine months ended September 30, 2021, the Company also cancelled 16,655,197 shares of restricted stock granted to holders of series A redeemable convertible preferred shares (see Note 10 to the condensed unaudited consolidated financial statements below).
Summary of Share-based Compensation Arrangements by Share-based Payment Award	20 Day VWAP of Class A common stock Below $10 $10.00 $12.50 $15.00 $18.50 $22.00 Percentage of target PSUs 0% 25% 50% 100% 150% 200%

Warrants and Derivative Liabi_2

Warrants and Derivative Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Warrants and Rights Note Disclosure [Abstract]
Summary of Fair Value Measurements Inputs	The following assumptions were used to determine the fair value of the warrants and derivative liabilities as of September 30, 2021 and December 31, 2020: As of September 30, 2021 As of December 31, 2020 Stock price $ — $ 7.56 Exercise price $ — $ 0.01 Risk-free interest rate — 0.09% Expected volatility — 64.0% Time to maturity (in years) — 0.63

Fair Value Disclosures (Tables)

Fair Value Disclosures (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Summary of Financial Instruments Measured At Fair Value On a Recurring Basis	The following table represents the fair value of the financial instruments measured at fair value on a recurring basis: As of September 30, 2021 Level 1 Level 2 Level 3 Total Assets Cash and cash equivalents* $ 5,764 $ — $ — $ 5,764 Total assets measured at fair value $ 5,764 $ — $ — $ 5,764 Liabilities Derivative liability $ — $ — $ — $ — Warrant liability — — — — Acquisition related liabilities — — 24,886 24,886 Total liabilities measured at fair value $ — $ — $ 24,886 $ 24,886 As of December 31, 2020 Assets Level 1 Level 2 Level 3 Total Cash and cash equivalents* $ 12,257 $ — $ — $ 12,257 Total assets measured at fair value $ 12,257 $ — $ — $ 12,257 Liabilities Derivative liability $ — $ — $ 38,400 $ 38,400 Warrant liability — — 19,700 19,700 Acquisition related liabilities — — 23,155 23,155 Total liabilities measured at fair value $ — $ — $ 81,255 $ * Includes cash invested by the Company in certain money market accounts with a financial institution.
Summary of Reconciliations of Changes In The Fair Value of The Liabilities	The following table reconciles the changes in the fair value of the liabilities categorized within Level 3 of the fair value hierarchy for the nine months ended September 30, 2021 and year ended December 31, 2020: Warrant Acquisition Derivative Balance as of January 1, 2021 $ 19,700 $ 23,155 $ 38,400 Additions, net of payments — 1,744 — Change in fair value 4,400 (13) 600 Extinguishment of the warrant and derivative liabilities (24,100) — (39,000) Balance as of September 30, 2021 $ — $ 24,886 $ —

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Common Stockholders (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Summary of basic and diluted net loss per share	The following table sets forth the calculation of basic and diluted net loss per share attributable to common stockholders during the periods presented: Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Net loss $ (69,129) $ (13,003) $ (188,425) $ (44,437) Cumulative redeemable convertible preferred stock dividends — 3,774 7,060 11,150 Numerator for Basic and Dilutive loss per share - loss available to common stockholders $ (69,129) $ (16,777) $ (195,485) $ (55,587 ) Denominator: Class A common stock 111,312,720 — 50,027,683 — Class B common stock 18,419,260 — 7,300,725 — Series A common stock — 26,108,711 14,420,964 26,108,727 Series B common stock — 3,054,318 1,664,380 3,054,318 Warrants (convertible to Series A common stock) — 3,444,328 1,899,768 3,444,328 Denominator for Basic and Dilutive loss per share-weighted-average common stock 129,731,980 32,607,357 75,313,520 32,607,373 Basic loss per share $ (0.53) $ (0.51) $ (2.60) $ (1.70) Dilutive loss per share $ (0.53) $ (0.51) $ (2.60) $ (1.70)
Schedule of Anti-Dilutive Common Equivalent Shares	Anti-dilutive common equivalent shares were as follows: Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Options (convertible to Series A common stock) 923,750 1,137,026 923,750 1,137,026 Warrants (convertible to Series A common stock) — 1,973,763 — 1,973,763 Redeemable convertible preferred stock — 39,223,194 — 39,223,194 Restricted stock and restricted stock units 64,360,347 84,486,332 64,360,347 84,486,332 Performance stock units 1,500,000 — 1,500,000 —

Organization and Background - A

Organization and Background - Additional Information (Detail) - USD ($)	Jun. 14, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2020	Sep. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Product Information [Line Items]
Proceeds from initial public offering					$ 126,538,000
Other offering costs and reimbursements	$ 6,200,000
Preferred stock, shares authorized		200,000,000			200,000,000
Preferred stock par value		$ 0.001			$ 0.001
Common Class A [Member]
Product Information [Line Items]
Stock issued during the period shares			14,773,939
Common stock, shares authorized		3,750,000,000			3,750,000,000
Common stock, par or stated value per share		$ 0.001			$ 0.001
Common stock, shares outstanding	152,270,401	155,022,167			155,022,167
Stock issued during period, shares conversion of units					73,813,713
Share issued in exercise of warrants		8,360,331			8,360,331
Shares repurchased (in shares)		37,679	4,138,866
Common Class A [Member] | Co-Founder and Chief Executive Officer [Member]
Product Information [Line Items]
Shares issued in connection with an agreement (in shares)					39,463,787
Common Class B [Member]
Product Information [Line Items]
Common stock, shares authorized		50,000,000			50,000,000
Common stock, par or stated value per share		$ 0.001			$ 0.001
Common stock, shares outstanding		37,856,095			37,856,095	37,856,095
Shares repurchased (in shares)		0	2,307,692		2,307,692
Convertible Preferred Stock [Member]
Product Information [Line Items]
Preferred stock, shares outstanding		39,223,194			39,223,194
Series A Common Stock [Member]
Product Information [Line Items]
Common stock, shares authorized							204,220,800
Common stock, par or stated value per share							$ 0.001
Common stock, shares outstanding							112,012,693
Shares issued in connection with an agreement (in shares)				154,560
Reclassification of temporary to permanent equity					26,722,208
Series B Common Stock [Member]
Product Information [Line Items]
Common stock, shares authorized							3,400,000
Common stock, par or stated value per share							$ 0.001
Common stock, shares outstanding							3,054,318
Reclassification of temporary to permanent equity					3,054,318
Restricted Series A Common Stock [Member]
Product Information [Line Items]
Shares repurchased (in shares)					4,138,866
Shares issued in connection with an agreement (in shares)					4,138,866
Reclassification of temporary to permanent equity					70,108,628
Restricted Series B Common Stock [Member]
Product Information [Line Items]
Shares issued in connection with an agreement (in shares)					540,000
Restricted Stock [Member] | Tax Withholding Repurchase [Member]
Product Information [Line Items]
Stock redeemed or called during period, shares					92,671
Restricted Stock [Member] | Tax Withholding Repurchase [Member] | Common Class A [Member]
Product Information [Line Items]
Stock repurchase program, number of shares authorized to be repurchased		1,799,650			1,799,650
Restricted Stock [Member] | Tax Withholding Repurchase [Member] | Common Class B [Member]
Product Information [Line Items]
Stock repurchase program, number of shares authorized to be repurchased		197,490			197,490
Restricted Stock [Member] | Class A Stock Repurchase [Member] | Common Class A [Member]
Product Information [Line Items]
Stock repurchase program, number of shares authorized to be repurchased		2,158,027			2,158,027
Stock redeemed or called during period, shares					88,518
Restricted Stock [Member] | Class B Stock Repurchase [Member] | Common Class B [Member]
Product Information [Line Items]
Stock repurchase program, number of shares authorized to be repurchased		1,767,692			1,767,692
Stock redeemed or called during period, shares					342,510
IPO [Member]
Product Information [Line Items]
Stock issued during the period shares	14,773,939
Sale of stock issue price per share	$ 10
Proceeds from initial public offering	$ 132,700,000
IPO [Member] | Restricted Series A Common Stock [Member]
Product Information [Line Items]
Shares Vested					8,734,893

Basis of Presentation and Sum_4

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2021USD ($)Segment	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Accounting Policies [Line Items]
Contract assets	$ 2,507		$ 1,748
Amount billed and collected in advance	34,175	$ 20,760
Revenue recognised out of advance receipt	35,489	$ 20,576
Deferred revenue	$ 2,739		$ 4,053
Number of operating segments | Segment	1
Accounts Receivable [Member] | Customer Concentration Risk [Member] | No Major Customer [Member]
Accounting Policies [Line Items]
Concentration risk percentage	0.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Maximum [Member]
Accounting Policies [Line Items]
Concentration risk percentage			14.00%

Basis of Presentation and Sum_5

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Disaggregation of Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Revenues	$ 115,133	$ 95,284	$ 323,492	$ 253,674
Direct Platform Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	84,663	63,346	242,219	180,589
Integrated Platform Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 30,470	$ 31,938	$ 81,273	$ 73,085

Basis of Presentation and Sum_6

Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Revenues and Long-lived Assets by Geographic Region are Based on the Physical Location of the Customers Being Served or the Assets (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 115,133	$ 95,284	$ 323,492	$ 253,674
Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	115,133	95,284	323,492	253,674
Long-lived assets	44,346		44,346		$ 39,008
Operating Segments [Member] | US [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	108,034	88,014	301,548	234,565
Long-lived assets	43,734		43,734		38,413
Operating Segments [Member] | International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	7,099	$ 7,270	21,944	$ 19,109
Long-lived assets	$ 612		$ 612		$ 595

Intangible Assets - Summary of

Intangible Assets - Summary of Intangible Assets and Related Accumulated Amortization (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross value	$ 82,671	$ 68,251
Accumulated amortization	53,739	39,660
Net value	28,932	28,591
Publisher and data supply relationships
Finite-Lived Intangible Assets [Line Items]
Gross value	7,500
Accumulated amortization	1,146
Net value	6,354
Trade names
Finite-Lived Intangible Assets [Line Items]
Gross value	2,720	2,720
Accumulated amortization	2,040	1,634
Net value	680	1,086
Completed technologies
Finite-Lived Intangible Assets [Line Items]
Gross value	20,292	20,292
Accumulated amortization	16,352	13,037
Net value	3,940	7,255
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross value	52,159	45,239
Accumulated amortization	34,201	24,989
Net value	$ 17,958	$ 20,250

Intangible Assets - Additional

Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Intangible Assets Disclosure [Abstract]
Amortization expense	$ 5,051	$ 3,913	$ 14,079	$ 11,754
Weighted average useful life of the unamortized intangibles			2 years 1 month 6 days

Intangible Assets - Summary o_2

Intangible Assets - Summary of Total Estimated Future Amortization Expense (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remaining three months of 2021	$ 4,952
2022	15,332
2023	6,040
2024	2,002
2025	482
2026 and thereafter	124
Total	$ 28,932	$ 28,591

Goodwill - Summary of Goodwill

Goodwill - Summary of Goodwill (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Goodwill [Line Items]
Balance as of January 1, 2021	$ 76,432
Foreign currency translation	(3)
Balance as of September 30, 2021	81,917
Vital [Member]
Goodwill [Line Items]
Acquisition	3,910
Kinetic [Member]
Goodwill [Line Items]
Acquisition	$ 1,578

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 03, 2021	Mar. 01, 2021	Sep. 30, 2021	Dec. 31, 2020
Business Acquisition, Date of Acquisition Agreement
Recognized of customer relationships as goodwill			$ 81,917	$ 76,432
Kinetic Data Solutions, LLC [Member]
Business Acquisition, Date of Acquisition Agreement
Business combination, purchase consideration		$ 2,762
Recognized of customer relationships intangibles		1,600
Recognized of customer relationships as goodwill		1,578
Recognized customer relationships as deferred tax liabilities		$ 416
Date of agreement		Mar. 1, 2021
Name of acquired entity		Kinetic Data Solutions, LLC (“Kinetic”)
Kinetic Data Solutions, LLC [Member] | Series A Common Stock [Member]
Business Acquisition, Date of Acquisition Agreement
Business acquisition, number of shares		306,749
Business combination, fair value		$ 2,738
Vital Digital, Corp [Member]
Business Acquisition, Date of Acquisition Agreement
Business combination, purchase consideration	$ 7,894
Recognized of customer relationships intangibles	5,320
Recognized of customer relationships as goodwill	3,910
Recognized customer relationships as deferred tax liabilities	$ 1,385
Date of agreement	Mar. 3, 2021
Name of acquired entity	Vital Digital, Corp (“Vital”)
Earnouts based on the operating performance	$ 1,206
Business combination, cash holdback	578
Other net assets	49
Payments to acquire businesses in cash	$ 3,400
Vital Digital, Corp [Member] | Caivis [Member]
Business Acquisition, Date of Acquisition Agreement
Percentage of interest acquired	5.00%
Vital Digital, Corp [Member] | Series A Common Stock [Member]
Business Acquisition, Date of Acquisition Agreement
Business acquisition, number of shares	306,748
Business combination, fair value	$ 2,710

Acquisition Related Liabiliti_3

Acquisition Related Liabilities - Schedule of Acquisition Related Liabilities (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Oct. 14, 2021
Schedule of acquisition related liabilities [Line Items]
Balance as of January 1, 2021	$ 23,155
Additions	1,808
Payments made during the year	(64)
Change in fair value of earn-out	(13)
Balance as of September 30, 2021	24,886
eBay CRM [Member]
Schedule of acquisition related liabilities [Line Items]
Balance as of January 1, 2021	17,137
Additions		$ 649
Change in fair value of earn-out	649
Balance as of September 30, 2021	17,786
Sizmek [Member]
Schedule of acquisition related liabilities [Line Items]
Balance as of January 1, 2021	4,402
Change in fair value of earn-out	(470)
Balance as of September 30, 2021	3,932
PlaceIQ [Member]
Schedule of acquisition related liabilities [Line Items]
Balance as of January 1, 2021	256
Payments made during the year	(64)
Change in fair value of earn-out	(192)
IgnitionOne [Member]
Schedule of acquisition related liabilities [Line Items]
Balance as of January 1, 2021	1,360
Balance as of September 30, 2021	1,360
Kinetic Data Solutions, LLC [Member]
Schedule of acquisition related liabilities [Line Items]
Additions	24
Balance as of September 30, 2021	24
Vital Digital, Corp [Member]
Schedule of acquisition related liabilities [Line Items]
Additions	1,784
Balance as of September 30, 2021	$ 1,784

Acquisition Related Liabiliti_4

Acquisition Related Liabilities - Additional Information (Detail) - USD ($) $ in Thousands	Oct. 14, 2021	Sep. 30, 2021
Schedule of acquisition related liabilities [Line Items]
Additions		$ 1,808
eBay CRM [Member]
Schedule of acquisition related liabilities [Line Items]
Payments made during the year	$ 9,786
Business combination liabilities from contingencies	9,137	8,000
Additions	$ 649
Letter of Credit [Member]
Schedule of acquisition related liabilities [Line Items]
Amount payable		$ 6,028

Credit Facilities - Summary of

Credit Facilities - Summary of Long-Term Borrowings (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Line of Credit Facility [Line Items]
Total borrowings	$ 185,000	$ 190,550
Less:Unamortized discount on debt		(426)
Less:Unamortized deferred financing cost	(1,472)	(431)
Long term borrowings	183,528	189,693
Credit facility [Member]
Line of Credit Facility [Line Items]
Total borrowings	$ 185,000	137,950
Loan under paycheck protection program [Member]
Line of Credit Facility [Line Items]
Total borrowings		10,000
Revolving loan [Member]
Line of Credit Facility [Line Items]
Total borrowings		$ 42,600

Credit Facilities - Summary o_2

Credit Facilities - Summary of Maturities of Long-term Debt (Parenthetical) (Detail) $ in Thousands	Sep. 30, 2022USD ($)
Line of Credit Facility [Abstract]
Repayable of long term debt	$ 4,219

Credit Facilities - Additional

Credit Facilities - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 10, 2021	Feb. 03, 2021	Dec. 31, 2020	Apr. 23, 2020	Jul. 31, 2015	Sep. 30, 2021	Sep. 30, 2020
Line of Credit Facility [Line Items]
Maximum revolving advance amount						$ 50,000
Repayments of long-term lines of credit		$ 42,792				$ 180,745	$ 3,500
Total leverage ratio						4
Fixed charge coverage ratio						1.25
Line of Credit [Member]
Line of Credit Facility [Line Items]
Outstanding balance of the revolving loan						$ 7,272
Small Business Administration [Member] | Small Business Administration To Paycheck Protection Program [Member]
Line of Credit Facility [Line Items]
Extinguishment of debt, amount	$ 10,000
Senior Debt Obligations [Member]
Line of Credit Facility [Line Items]
Secured debt		222,500				222,500
Debt issuance costs						$ 1,699
Debt instrument, maturity date						Feb. 3, 2026
Line of credit facility, remaining borrowing capacity						$ 37,500
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Outstanding balance of the revolving loan			$ 42,600
Revolving Credit Facility [Member] | Senior Debt Obligations [Member]
Line of Credit Facility [Line Items]
Line of credit facility, current borrowing capacity						73,750
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Outstanding balance of the revolving loan			7,272
Term Facility [Member] | Senior Debt Obligations [Member]
Line of Credit Facility [Line Items]
Line credit facility initial term loan withdrawn at closing date						$ 111,250
Paycheck Protection Program [Member]
Line of Credit Facility [Line Items]
Debt instrument, maturity date				Apr. 24, 2022
Long-term line of credit				$ 10,000
Interest rate during period				1.00%
Term Loan Facility [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Maximum revolving advance amount					$ 142,950
Repayments of long-term lines of credit		$ 137,953
Line of credit facility, remaining borrowing capacity			$ 5,000
Line of credit facility incremental term loan					40,000
Line of credit facility delay drawn term loan					32,950
Line credit facility initial term loan withdrawn at closing date					$ 70,000
Prime Rate [Member]
Line of Credit Facility [Line Items]
Interest charged on outstanding balance, Interest rate						1.25%
London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Interest charged on outstanding balance, Interest rate						2.25%
London Interbank Offered Rate (LIBOR) [Member] | Senior Debt Obligations [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Interest charged on outstanding balance, Interest rate						2.625%
London Interbank Offered Rate (LIBOR) [Member] | Senior Debt Obligations [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Interest charged on outstanding balance, Interest rate						2.125%
London Interbank Offered Rate (LIBOR) [Member] | Term Facility [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of credit facility, interest rate description					LIBOR+7.5
London Interbank Offered Rate (LIBOR) [Member] | Term Loan Facility [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Debt instrument, interest rate during period					1.00%

Credit Facilities - Summary o_3

Credit Facilities - Summary of Maturities of Long-term Debt (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Line of Credit Facility [Abstract]
Remaining three months of 2021	$ 0
2022	5,625
2023	11,250
2024	11,250
2025	16,875
2026 and thereafter	140,000
Total*	$ 185,000	$ 190,550

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Other Current And Noncurrent Liabilities [Member]
Commitments And Contingencies Disclosure [Line Items]
Deferred rent	$ 2,458	$ 2,652

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Commitments For The Base Rents (Detail) $ in Thousands	Sep. 30, 2021USD ($)
Commitments and Contingencies Disclosure [Abstract]
Remaining three months of 2021	$ 778
2022	2,553
2023	2,133
2024	1,953
2025	1,788
2026 and thereafter	5,062
Total	$ 14,267

Commitments and Contingencies_3

Commitments and Contingencies - Summary of Long-term Purchase Commitment (Detail) $ in Thousands	Sep. 30, 2021USD ($)
Commitments and Contingencies Disclosure [Abstract]
Remaining three months of 2021	$ 2,468
2022	9,785
2023	5,700
2024	5,700
2025	5,700
2026 and thereafter	1,425
Total	$ 30,778

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of The Activity of Restricted Stock And Restricted Stock Units Granted By The Company (Detail)	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Share-based Payment Arrangement, Disclosure [Abstract]
Non-vested as of January 1, 2021 | shares	85,903,970
Granted | shares	9,112,569
Vested | shares	(9,300,893)
Forfeited | shares	(4,700,102)
Cancelled | shares	(16,655,197)
Modified | shares	(68,986,297)
Modified and reissued | shares	68,986,297
Non-vested as of September 30, 2021 | shares	64,360,347
Non-vested as of January 1, 2021 | $ / shares	$ 2.80
Granted | $ / shares	8.62
Vested | $ / shares	11.04
Forfeited | $ / shares	9.46
Cancelled | $ / shares	3.60
Modified | $ / shares	2.78
Modified and reissued | $ / shares	11.36
Non-vested as of September 30, 2021 | $ / shares	$ 10.94

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of The Activity of Restricted Stock And Restricted Stock Units Granted By The Company (Parenthetical) (Detail) - shares	Mar. 12, 2021	Sep. 30, 2021
Share-based compensation arrangement by share-based payment award, award vesting period	4 years
IPO [Member]
Share-based compensation arrangement by share-based payment award, award vesting period	1 year
Percentage of vesting of restricted stock and restricted stock units	25.00%
Restricted Stock [Member]
Number of shares available for grant	1,660,677	8,824,045
Number of shares forfeited during period		4,682,178
Restricted Stock Units (RSUs) [Member]
Number of shares available for grant	98,993	288,724
Stock issued during period, shares, conversion of units		1,198,219
Number of shares forfeited during period		17,924
Series A Redeemable Convertible Preferred Shares [Member] | Restricted Stock [Member]
Number of shares cancelled during period		16,655,197

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Share-based Compensation Arrangements by Share-based Payment Award (Detail) - Common Class A [Member]	9 Months Ended
	Sep. 30, 2021$ / shares
Below $10
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
20 Day VWAP of Class A common stock	$ 10
Percentage of target PSUs	0.00%
$10.00
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
20 Day VWAP of Class A common stock	$ 10
Percentage of target PSUs	25.00%
$12.50
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
20 Day VWAP of Class A common stock	$ 12.50
Percentage of target PSUs	50.00%
$15.00
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
20 Day VWAP of Class A common stock	$ 15
Percentage of target PSUs	100.00%
$18.50
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
20 Day VWAP of Class A common stock	$ 18.50
Percentage of target PSUs	150.00%
$22.00
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
20 Day VWAP of Class A common stock	$ 22
Percentage of target PSUs	200.00%

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Aug. 18, 2021	Mar. 24, 2021	Mar. 12, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Aug. 01, 2021	Dec. 31, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period			4 years
Unrecognized compensation expense				$ 607,110		$ 607,110
Unrecognized compensation expense related to unvested restricted stock				64,360,347		64,360,347			85,903,970
Weighted average contractual years						1 year 4 months 13 days
share related expenses				$ 69,343	$ 26	$ 188,613	$ 79
IPO [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Percentage of vesting of restricted stock and restricted stock units			25.00%
Share-based compensation arrangement by share-based payment award, award vesting period			1 year
Restricted Stock And Restricted Stock Units [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Percentage of vesting of restricted stock and restricted stock units						25.00%
Share-based compensation arrangement by share-based payment award, award vesting period						5 years
Restricted Stock And Restricted Stock Units [Member] | Share-based Payment Arrangement, Tranche Two [Member] | IPO [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period deferred		1 year
Restricted Stock And Restricted Stock Units [Member] | Maximum [Member] | Share-based Payment Arrangement, Tranche One [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Percentage of vesting of restricted stock and restricted stock units		20.00%
Share-based compensation arrangement by share-based payment award, award vesting period		4 years
Restricted Stock And Restricted Stock Units [Member] | Maximum [Member] | Share-based Payment Arrangement, Tranche Two [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Percentage of vesting of restricted stock and restricted stock units		100.00%
Share-based compensation arrangement by share-based payment award, award vesting period		5 years
Restricted Stock And Restricted Stock Units [Member] | Maximum [Member] | Share-based Payment Arrangement, Tranche Three [Member] | IPO [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period		5 years
Restricted Stock And Restricted Stock Units [Member] | Minimum [Member] | Share-based Payment Arrangement, Tranche One [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period		1 year
Restricted Stock And Restricted Stock Units [Member] | Minimum [Member] | Share-based Payment Arrangement, Tranche Two [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Percentage of vesting of restricted stock and restricted stock units		25.00%
Share-based compensation arrangement by share-based payment award, award vesting period		5 years
Restricted Stock And Restricted Stock Units [Member] | Minimum [Member] | Share-based Payment Arrangement, Tranche Three [Member] | IPO [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period		1 year
Unvested Restricted Stock And Restricted Stock Units [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Unrecognized compensation expense related to unvested restricted stock				64,360,347		64,360,347
Performance Shares [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based Payment Award, Number of Shares Authorized	1,500,000			1,500,000		1,500,000
Wighted average exercise price				$ 1.95		$ 1.95
share related expenses				$ 86		$ 86
Performance Shares [Member] | Common Class A [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Issuance of shares	3,000,000
Employee Stock [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Wighted average exercise price								$ 2.16
share related expenses				$ 180		180
Stock Issued under Employee Stock Purchase Plan						10,000
Employee Stock [Member] | Common Class A [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Maximum Value of Shares Per Employee can purchase under the plan						$ 25,000

Stockholders' Equity _ (Defic_2

Stockholders' Equity / (Deficit) - Additional Information (Detail) - $ / shares	Sep. 30, 2021	Feb. 24, 2021	Jun. 14, 2021	Mar. 31, 2021
Class of Stock [Line Items]
Shares issued on settlement	200,000
Common Class A [Member]
Class of Stock [Line Items]
Common stock, shares, outstanding	155,022,167		152,270,401
Common Class A [Member] | Amended and Restated Certificate of Incorporation [Member]
Class of Stock [Line Items]
Common stock voting rights	one
Common Class B [Member]
Class of Stock [Line Items]
Common stock, shares, outstanding	37,856,095			37,856,095
Common Class B [Member] | Amended and Restated Certificate of Incorporation [Member]
Class of Stock [Line Items]
Common stock voting rights	ten
Series A Redeemable Convertible Preferred Shares [Member]
Class of Stock [Line Items]
Preferred stock, convertible, conversion price, decrease		$ 0.073587
Preferred stock, convertible, conversion price, increase		$ 0.59
Series A Redeemable Convertible Preferred Shares [Member] | Restricted Stock [Member]
Class of Stock [Line Items]
Number of shares forfeited during the period.		16,655,197

Warrants and Derivative Liabi_3

Warrants and Derivative Liabilities - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Warrants and Rights Note Disclosure [Abstract]
Warrants and derivative liabilities					$ 58,100
Fair value adjustment of warrants	$ 0	$ 9,700	$ 5,000	$ 16,400

Warrants and Derivative Liabi_4

Warrants and Derivative Liabilities - Summary of Fair Value Measurements Inputs (Detail)	Dec. 31, 2020yr$ / shares
Stock Price [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and derivative liabilities	7.56
Exercise Price [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and derivative liabilities	0.01
Risk-free Interest Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and derivative liabilities	0.09
Expected Volatility [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and derivative liabilities	64
Time To Maturity (in years) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants and derivative liabilities | yr	0.63

Fair Value Disclosures - Summar

Fair Value Disclosures - Summary of Financial Instruments Measured At Fair Value On a Recurring Basis (Detail) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets
Assets measured at fair value	$ 5,764	$ 12,257
Liabilities
Liabilities measured at fair value	24,886	81,255
Level 1 [Member]
Assets
Assets measured at fair value	5,764	12,257
Level 3 [Member]
Liabilities
Liabilities measured at fair value	24,886	81,255
Derivative Liability [Member]
Liabilities
Liabilities measured at fair value		38,400
Derivative Liability [Member] | Level 3 [Member]
Liabilities
Liabilities measured at fair value		38,400
Warrant Liability [Member]
Liabilities
Liabilities measured at fair value		19,700
Warrant Liability [Member] | Level 3 [Member]
Liabilities
Liabilities measured at fair value		19,700
Acquisition Related Liabilities [Member]
Liabilities
Liabilities measured at fair value	24,886	23,155
Acquisition Related Liabilities [Member] | Level 3 [Member]
Liabilities
Liabilities measured at fair value	24,886	23,155
Cash and Cash Equivalents [Member]
Assets
Assets measured at fair value	5,764	12,257
Cash and Cash Equivalents [Member] | Level 1 [Member]
Assets
Assets measured at fair value	$ 5,764	$ 12,257

Fair Value Disclosures - Summ_2

Fair Value Disclosures - Summary of Reconciliations of Changes In The Fair Value of The Liabilities (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Warrant Liability [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance as of January 1, 2021	$ 19,700
Change in fair value	4,400
Extinguishment of the warrant and derivative liabilities	(24,100)
Balance as of September 30, 2021
Acquisition Related Liabilities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance as of January 1, 2021	23,155
Additions, net of payments	1,744
Change in fair value	(13)
Balance as of September 30, 2021	24,886
Derivative Liability [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance as of January 1, 2021	38,400
Change in fair value	600
Extinguishment of the warrant and derivative liabilities	(39,000)
Balance as of September 30, 2021

Fair Value Disclosures - Additi

Fair Value Disclosures - Additional Information (Detail) $ in Thousands	Dec. 31, 2020USD ($)
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans payable, fair value disclosure	$ 152,538

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($) $ in Thousands	Apr. 09, 2012	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Caivis Group [Member]
Related Party Transaction [Line Items]
Repayments of debt				$ 533
Caivis Group [Member] | Accounts Payable and Accrued Liabilities [Member]
Related Party Transaction [Line Items]
Due to related party		$ 0		0		$ 533
Caivis Group [Member] | General Administrative And Corporate Development Support Activities [Member]
Related Party Transaction [Line Items]
Related party transaction fees payable per year	$ 2,000			0		0
Related party transaction fees	$ 2,000			0		0
Casting Made Simple Corp [Member] | Websites Traffic Monetization Agreement [Member]
Related Party Transaction [Line Items]
Related party costs		49	$ 92	211	$ 277
Casting Made Simple Corp [Member] | Websites Traffic Monetization Agreement [Member] | Accounts Payable and Accrued Liabilities [Member]
Related Party Transaction [Line Items]
Due to related party		$ 48		$ 48		$ 70

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income tax provision	$ 428	$ 301	$ (565)	$ 1,319
Effective tax rate	(0.62%)	(2.37%)
Loss before income taxes	$ 68,701	$ 12,702	$ 188,990	$ 43,118

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Common Stockholders - Additional Information (Detail) - shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Unvested restricted stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities	65,860,347	65,860,347
Restricted stock units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities	84,486,332	84,486,332

Net Loss Per Share Attributab_4

Net Loss Per Share Attributable to Common Stockholders - Summary of Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net loss	$ (69,129)	$ (94,922)	$ (24,374)	$ (13,003)	$ (15,054)	$ (16,380)	$ (188,425)	$ (44,437)
Cumulative redeemable convertible preferred stock dividends				3,774			7,060	11,150
Net loss available to common stockholders	$ (69,129)			$ (16,777)			$ (195,485)	$ (55,587)
Denominator:
Denominator for Basic and Dilutive Loss per share-Weighted-average Common Stock	129,731,980			32,607,357			75,313,520	32,607,373
Basic loss per share	$ (0.53)			$ (0.51)			$ (2.60)	$ (1.70)
Diluted loss per share	$ (0.53)			$ (0.51)			$ (2.60)	$ (1.70)
Class A Common Stock [Member]
Denominator:
Denominator for Basic and Dilutive Loss per share-Weighted-average Common Stock	111,312,720						50,027,683
Class B Common Stock [Member]
Denominator:
Denominator for Basic and Dilutive Loss per share-Weighted-average Common Stock	18,419,260						7,300,725
Series A Common Stock [Member]
Denominator:
Denominator for Basic and Dilutive Loss per share-Weighted-average Common Stock				26,108,711			14,420,964	26,108,727
Series B common stock [Member]
Denominator:
Denominator for Basic and Dilutive Loss per share-Weighted-average Common Stock				3,054,318			1,664,380	3,054,318
Warrant [Member]
Denominator:
Denominator for Basic and Dilutive Loss per share-Weighted-average Common Stock				3,444,328			1,899,768	3,444,328

Net Loss Per Share Attributab_5

Net Loss Per Share Attributable to Common Stockholders - Schedule of Anti-Dilutive Common Equivalent Shares (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Options (convertible to Series A common stock)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total anti-dilutive outstanding potential common stock	923,750	1,137,026	923,750	1,137,026
Warrants (convertible to Series A common stock)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total anti-dilutive outstanding potential common stock		1,973,763		1,973,763
Redeemable convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total anti-dilutive outstanding potential common stock		39,223,194		39,223,194
Restricted stock and restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total anti-dilutive outstanding potential common stock	64,360,347	84,486,332	64,360,347	84,486,332
Performance stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total anti-dilutive outstanding potential common stock	1,500,000		1,500,000

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Oct. 01, 2021	Sep. 30, 2021
Common Class A [Member]
Subsequent Event [Line Items]
Common stock par value		$ 0.001
Subsequent Event [Member] | Apptness Media Group, LLC [Member]
Subsequent Event [Line Items]
Payments to Acquire Businesses	$ 17,934
Minimum lock up period	18 months
Indemnity hold-back amount	$ 1,750
Earn-out consideration payable	$ 22,000
Percentage of consideration payable in cash	50.00%
Percentage of consideration payable in shares	50.00%
Subsequent Event [Member] | Apptness Media Group, LLC [Member] | Common Class A [Member]
Subsequent Event [Line Items]
Common stock par value	$ 0.001
Business Combination, Equity Interests Issued and Issuable	$ 23,000