Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Total revenue	$ 358,435	$ 208,357	$ 106,847
Operating expenses:
Operations and technology	101,056	64,998	39,626
Selling, general, and administrative	121,167	64,882	62,439
Depreciation and amortization	8,264	6,075	1,286
Total operating expenses	435,240	249,004	186,129
Loss from operations	(76,805)	(40,647)	(79,282)
Other income (expense):
Interest income	129	748	2,093
Interest expense	(782)	(633)	0
Total other income (expense)	(653)	115	2,093
Loss before income taxes	(77,458)	(40,532)	(77,189)
Provision for income taxes	724	489	27
Net loss	$ (78,182)	$ (41,021)	$ (77,216)
Weighted-average shares - basic and diluted	125,332,800	21,596,379	18,370,224
Net loss per share - basic and diluted	$ (0.62)	$ (1.90)	$ (4.20)
Marketplace And Service Revenue [Member]
Total revenue	$ 308,350	$ 173,120
Operating expenses:
Cost of revenue			$ 65,962
Customer Assurance Revenue [Member]
Total revenue	50,085	35,237
Operating expenses:
Cost of revenue			16,816
Marketplace And Service Cost [Member]
Total revenue			87,750
Operating expenses:
Cost of revenue	159,405	83,553
Customer Assurance Cost [Member]
Total revenue			$ 19,097
Operating expenses:
Cost of revenue	$ 45,348	$ 29,496