CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Sep. 30, 2021		Sep. 30, 2020		Sep. 30, 2021		Sep. 30, 2020
Income Statement [Abstract]
Revenue	[1]	$ 102,072		$ 59,955		$ 275,240		$ 162,392
Costs and expenses:
Cost of revenue	[1]	7,647		3,102		16,289		8,806
Research and development	[1]	13,162		4,369		30,584		13,253
Sales and marketing	[1]	114,531		73,187		310,377		172,381
General and administrative	[1]	48,376		7,861		101,092		24,336
Total costs and expenses	[1]	183,716		88,519		458,342		218,776
Loss from operations	[1]	(81,644)		(28,564)		(183,102)		(56,384)
Interest expense, net	[1]	(87)		(24)		(136)		(1,297)
Change in fair value of common stock warrant liabilities	[1]	113,601		0		81,898		0
Other income (expense), net	[1]	(22)		(14,216)		108		(20,749)
Income (loss) before income taxes	[1]	31,848		(42,804)		(101,232)		(78,430)
(Benefit) provision for income taxes	[1]	(18,933)		47		(18,826)		100
Net income (loss)		$ 50,781	[1]	$ (42,851)	[2]	$ (82,406)	[1]	$ (78,530)	[1]
Net income (loss) per share attributable to common stockholders - basic (in dollars per share)	[1]	$ 0.13		$ (0.14)		$ (0.22)		$ (0.27)
Weighted average common shares outstanding - basic (in shares)	[1]	395,053,445		298,713,456		379,450,553		288,958,713
Net loss attributable to common stockholders – diluted	[1]	$ (62,820)		$ (42,851)		$ (164,304)		$ (78,530)
Net loss per share attributable to common stockholders - diluted (in dollars per share)	[1]	$ (0.16)		$ (0.14)		$ (0.43)		$ (0.27)
Weighted average common shares outstanding - diluted (in shares)	[1]	396,030,131		298,713,456		385,451,806		288,958,713

[1] Retroactively restated for the reverse recapitalization as described in Notes 1 and 3.

[2] Retroactively restated for the reverse recapitalization as described in Notes 1 and 3.