Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Revenue	$ 16,564	$ 13,478	$ 48,402	$ 35,509
Cost of revenue	3,419	1,868	9,338	4,032
Gross profit	13,145	11,610	39,064	31,477
Operating expenses:
Technology and development	2,936	2,432	8,531	7,044
Sales and marketing	6,682	5,840	19,784	18,778
General and administrative	6,839	4,306	21,204	14,670
Restructuring costs	0	32	0	149
Depreciation and amortization	345	523	1,153	3,198
Total operating expenses	16,802	13,133	50,672	43,839
Loss from continuing operations	(3,657)	(1,523)	(11,608)	(12,362)
Interest expense and other income, net:
Interest expense	(1)	(27)	(2)	(74)
Other income, net	910	72	3,097	1,917
Total interest expense and other income, net	909	45	3,095	1,843
Loss from continuing operations before income taxes	(2,748)	(1,478)	(8,513)	(10,519)
Provision for income taxes	53	103	104	146
Loss from continuing operations, net of income taxes	(2,801)	(1,581)	(8,617)	(10,665)
Loss on sale of discontinued operations, net of income taxes	0	0	0	(136)
Net loss	$ (2,801)	$ (1,581)	$ (8,617)	$ (10,801)
Net loss per share — basic and diluted:
Loss from continuing operations, net of income taxes (usd per share)	$ (0.06)	$ (0.03)	$ (0.19)	$ (0.21)
Loss from discontinued operations, net of income taxes (usd per share)	0	0	0	0
Net loss (usd per share)	$ (0.06)	$ (0.03)	$ (0.19)	$ (0.21)
Weighted-average number of shares of common stock outstanding:
Basic and diluted (shares)	46,158,465	52,716,626	45,579,435	52,265,228