CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues, net	$ 7,275	$ 12,476	$ 15,935	$ 25,924
Cost of revenues	4,585	5,929	9,930	11,740
Gross profit	2,690	6,547	6,005	14,184
Operating expenses
Sales and marketing	1,880	4,087	4,192	8,721
Research and development	3,338	4,660	6,775	9,555
General and administrative	2,011	2,277	3,992	5,498
Total operating expenses	7,229	11,024	14,959	23,774
Loss from operations	(4,539)	(4,477)	(8,954)	(9,590)
Other income, net	537	532	1,006	1,072
Loss before provision for income taxes	(4,002)	(3,945)	(7,948)	(8,518)
(Benefit from) provision for income taxes	(521)	58	(496)	91
Net loss	(3,481)	(4,003)	(7,452)	(8,609)
Foreign currency translation adjustments	5	76	88	5
Comprehensive loss	$ (3,476)	$ (3,927)	$ (7,364)	$ (8,604)
Net loss per share available to common stockholders, basic and diluted (Note 11)	$ (0.50)	$ (0.65)	$ (1.09)	$ (1.42)
Weighted-average shares used to compute net loss per share available to common stockholders, basic and diluted	6,912	6,201	6,866	6,074
Stock-based compensation expense	$ 567	$ 762	$ 1,013	$ 1,447
Amortization of intangible assets			95	1,000
Cost of Revenues [Member]
Operating expenses
Stock-based compensation expense	129	142	223	267
Amortization of intangible assets	0	234	47	468
Restructuring related expenses	0	0	(7)	6
Sales and Marketing [Member]
Operating expenses
Stock-based compensation expense	149	205	259	385
Amortization of intangible assets	0	0	0	64
Restructuring related expenses	0	66	50	223
Research and Development [Member]
Operating expenses
Stock-based compensation expense	217	269	384	550
Amortization of intangible assets	0	234	48	468
General and Administrative [Member]
Operating expenses
Stock-based compensation expense	$ 72	$ 146	$ 147	$ 245