Consolidated Statements of Income and Comprehensive Income - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenues		$ 36,244	$ 33,809	$ 102,456	$ 98,067
Cost of revenues	[1]	9,212	8,047	26,148	23,011
Gross profit		27,032	25,762	76,308	75,056
Operating expenses:
Selling and marketing	[1]	13,792	12,454	39,311	38,877
Product development	[1]	1,961	2,085	5,839	6,073
General and administrative	[1]	3,355	3,107	9,976	9,252
Depreciation and amortization, excluding depreciation of $274, $94, $666, and $163, respectively, included in cost of revenues		1,452	1,205	4,250	3,481
Total operating expenses		20,560	18,851	59,376	57,683
Operating income		6,472	6,911	16,932	17,373
Interest and other income (expense), net		91	(409)	(388)	(798)
Income before provision for income taxes		6,563	6,502	16,544	16,575
(Benefit) Provision for income taxes		(219)	1,151	2,782	3,783
Net income		6,782	5,351	13,762	12,792
Other comprehensive income (loss), net of tax:
Unrealized income (loss) on investments (net of tax provision of $3, $0, $(10), and $0, respectively)		12		(36)
Foreign currency translation gain (loss)		210	(235)	178	(252)
Other comprehensive income (loss)		222	(235)	142	(252)
Comprehensive income		$ 7,004	$ 5,116	$ 13,904	$ 12,540
Net income per common share:
Basic		$ 0.24	$ 0.19	$ 0.50	$ 0.46
Diluted		$ 0.24	$ 0.19	$ 0.48	$ 0.45
Weighted average common shares outstanding:
Basic		27,781	27,910	27,773	27,785
Diluted		28,473	28,370	28,412	28,253

[1] Amounts include stock-based compensation expense as follows: