CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenue	$ 384,089	$ 230,115	$ 119,872
Costs and expenses:
Cost of revenue	24,711	12,281	5,713
Research and development	46,017	23,225	11,241
Sales and marketing	465,457	251,941	111,370
General and administrative	135,026	42,289	16,376
Total costs and expenses	671,211	329,736	144,700
Loss from operations	(287,122)	(99,621)	(24,828)
Interest expense, net	(1,222)	(1,325)	(2,497)
Change in fair value of common stock warrant liabilities	87,922	(23,049)	0
Other income (expense), net	49	(21,400)	3,720
Loss before income taxes	(200,373)	(145,395)	(23,605)
(Benefit) provision for income taxes	(18,996)	115	0
Net loss	$ (181,377)	$ (145,510)	$ (23,605)
Net loss per share attributable to common stockholders:
Basic (in dollars per share)	$ (0.47)	$ (0.49)	$ (0.09)
Diluted (in dollars per share)	$ (0.69)	$ (0.49)	$ (0.09)
Weighted average shares outstanding:
Basic (in shares)	384,625,249	294,549,146	261,228,108
Diluted (in shares)	388,549,673	294,549,146	261,228,108
Other comprehensive loss:
Change in unrealized loss on available-for-sale investments, net of tax	$ (248)	$ 0	$ 0
Total other comprehensive loss:	(248)	0	0
Comprehensive loss:	$ (181,625)	$ (145,510)	$ (23,605)