CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Revenue	$ 129,561	$ 118,327	$ 392,323	$ 345,823
Costs and expenses
Cost of revenue	43,681	38,795	138,297	112,377
Sales and marketing	49,448	40,852	167,563	116,427
General and administrative	32,171	17,193	92,152	47,784
Product development	44,744	41,734	156,568	112,715
Restructuring costs	7,111	44	17,949	3,269
Amortization of purchased intangibles	920	488	2,742	1,237
Total costs and expenses	178,075	139,106	575,271	393,809
Loss from operations	(48,514)	(20,779)	(182,948)	(47,986)
Other income (expense), net:
Interest income (expense), net	401	(9,442)	(1,713)	(27,852)
Other income (expense), net	5,114	(48)	1,908	3,002
Total other income (expense), net	5,515	(9,490)	195	(24,850)
Loss before provision for income taxes	(42,999)	(30,269)	(182,753)	(72,836)
Provision for income taxes	249	2,538	1,270	2,285
Net loss	$ (43,248)	$ (32,807)	$ (184,023)	$ (75,121)
Net loss per share of common stock:
Basic net loss per common share (in dollars per share)	$ (0.56)	$ (0.47)	$ (2.39)	$ (1.09)
Diluted net loss per common share (in dollars per share)	$ (0.56)	$ (0.47)	$ (2.39)	$ (1.09)
Weighted-average shares used to compute net loss per share:
Weighted average shares outstanding used in basic net loss per common share calculation (in shares)	77,784,346	69,798,839	76,969,629	68,926,203
Weighted average shares outstanding used in diluted net loss per common share calculation (in shares)	77,784,346	69,798,839	76,969,629	68,926,203