CONSOLIDATED STATEMENTS OF OPERATIONS (unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
Revenue	$ 134	$ 656	$ 323	$ 1,428
Cost of revenue	92	272	217	607
Gross profit	42	384	106	821
Operating expenses:
Sales and marketing	56	396	101	866
Product development	46	52	112	103
General and administrative	31	50	46	92
Total operating expenses	133	498	259	1,061
Loss from operations	(91)	(114)	(153)	(240)
Other income, net:
Interest and other income, net	2	8	4	8
Loss before provision for income taxes	(89)	(106)	(149)	(232)
Provision for income taxes	1	5	1	7
Net loss	$ (90)	$ (111)	$ (150)	$ (239)
Net loss per share, basic	$ (0.13)	$ (0.18)	$ (0.23)	$ (0.38)
Net loss per share, diluted	$ (0.13)	$ (0.18)	$ (0.23)	$ (0.38)
Weighted-average shares used in computing net loss per share, basic	667	624	664	621
Weighted-average shares used in computing net loss per share, diluted	667	624	664	621