Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue:
Total revenue	$ 41,456	$ 33,460	$ 109,523	$ 89,263
Operating expenses:
Product costs (exclusive of amortization of intangible assets shown separately below)	16,202	15,385	42,003	37,456
Service costs (exclusive of amortization of intangible assets shown separately below)	8,229	4,993	21,077	15,881
Sales and marketing	8,796	6,973	23,644	20,893
Product development	5,558	4,558	15,362	14,337
General and administrative	7,615	7,056	22,584	21,933
Amortization of intangible assets	1,133	1,313	3,115	4,547
Total operating expenses	47,533	40,278	127,785	115,047
Loss from operations	(6,077)	(6,818)	(18,262)	(25,784)
Interest income	116	66	164	148
Interest expense	(2)	(2)	(4)	(5)
Other expense, net	(59)	(6)	(92)	(9)
Loss before income taxes	(6,022)	(6,760)	(18,194)	(25,650)
Income tax expense	(13)	(57)	(59)	(150)
Net loss	$ (6,035)	$ (6,817)	$ (18,253)	$ (25,800)
Net loss per share - basic and diluted (in dollars per share)	$ (0.24)	$ (0.33)	$ (0.75)	$ (1.27)
Weighted average number of shares - basic and diluted (in shares)	25,111	20,745	24,315	20,363
Product
Revenue:
Total revenue	$ 22,482	$ 20,908	$ 58,125	$ 50,841
Service
Revenue:
Total revenue	$ 18,974	$ 12,552	$ 51,398	$ 38,422