CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue
Revenues, net	$ 12,476	$ 14,251	$ 25,924	$ 29,653
Cost of revenues	5,929	6,963	11,740	14,535
Gross profit	6,547	7,288	14,184	15,118
Operating expenses
Sales and marketing	4,087	6,154	8,721	13,535
Research and development	4,660	5,817	9,555	11,972
General and administrative	2,277	3,766	5,498	7,143
Total operating expenses	11,024	15,737	23,774	32,650
Loss from operations	(4,477)	(8,449)	(9,590)	(17,532)
Other income, net	532	377	1,072	672
Loss before provision for income taxes	(3,945)	(8,072)	(8,518)	(16,860)
Provision for income taxes	58	204	91	528
Net loss	(4,003)	(8,276)	(8,609)	(17,388)
Foreign currency translation adjustments	76	(578)	5	(134)
Comprehensive loss	$ (3,927)	$ (8,854)	$ (8,604)	$ (17,522)
Net loss per share available to common stockholders, basic and diluted (Note 11) (in dollars per share)	$ (0.65)	$ (1.44)	$ (1.42)	$ (3.02)
Weighted-average shares used to compute net loss per share available to common stockholders, basic and diluted (in shares)	6,201	5,767	6,074	5,751
Stock-based compensation expense	$ 762	$ 1,030	$ 1,447	$ 2,058
Amortization of intangible assets	468	651	1,000	1,341
Cost of Revenues [Member]
Operating expenses
Stock-based compensation expense	142	172	267	376
Amortization of intangible assets	234	233	468	470
Restructuring related expenses	0	0	6	139
Sales and Marketing [Member]
Operating expenses
Stock-based compensation expense	205	271	385	511
Amortization of intangible assets	0	184	64	397
Restructuring related expenses	66	48	223	545
Research and Development [Member]
Operating expenses
Stock-based compensation expense	269	314	550	653
Amortization of intangible assets	234	234	468	471
Restructuring related expenses	0	0	0	115
General and Administrative [Member]
Operating expenses
Stock-based compensation expense	146	273	245	518
Amortization of intangible assets	0	0	0	3
Restructuring related expenses	$ 0	$ 36	$ 0	$ 147