CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 633,042	$ 654,152
Accounts receivable, net of allowances of $5,601 and $5,344 as of September 30, 2021 and December 31, 2020, respectively	83,160	80,423
Prepaid expenses and other current assets	26,489	14,236
Total current assets	742,691	748,811
Operating lease right of use assets (Note 10)	1,957	614
Property and equipment, net (Note 6)	118,726	106,055
Contract acquisition costs	43,705	41,021
Intangibles, net (Note 5)	18,134	10,927
Goodwill (Note 5)	139,149	95,192
Deferred tax assets	3,534	2,032
Other assets	1,013	1,780
Total assets	1,068,909	1,006,432
Current liabilities:
Accounts payable	14,599	14,115
Accrued expenses and other current liabilities (Note 7)	105,596	99,870
Deferred revenue (Note 2)	102,905	88,848
Operating lease liability (Note 10)	3,257	5,718
Total current liabilities	226,357	208,551
Deferred revenue, net of current portion (Note 2)	179	409
Convertible senior notes, net (Note 8)	565,059	538,432
Operating lease liability, net of current portion (Note 10)	3,415	7,180
Deferred tax liability	1,995	1,622
Other liabilities	9,795	6,304
Total liabilities	806,800	762,498
Commitments and contingencies (Note 12)
Stockholders’ equity:
Preferred stock, $0.001 par value - 5,000,000 shares authorized, none issued	0	0
Common stock, $0.001 par value - 200,000,000 shares authorized, 72,723,049 and 70,264,265 shares issued, 70,013,219 and 67,554,435 shares outstanding as of September 30, 2021 and December 31, 2020, respectively	73	70
Additional paid-in capital	733,202	635,672
Treasury stock - 2,709,830 shares	(3)	(3)
Accumulated deficit	(467,006)	(391,885)
Accumulated other comprehensive (loss) income	(4,157)	80
Total stockholders’ equity	262,109	243,934
Total liabilities and stockholders’ equity	$ 1,068,909	$ 1,006,432