Unaudited 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	$ 2,665	$ 1,678	$ 7,296	$ 4,780
Cost of revenue	967	736	2,744	1,951
Gross profit	1,698	942	4,552	2,829
Operating expenses:
Sales and marketing	466	394	1,311	1,169
Research and development	329	617	832	1,797
General and administrative	243	242	828	855
Operating income (loss)	660	(311)	1,581	(992)
Other income		928		928
Interest expense, net	(43)	(49)	(144)	(157)
Net income (loss)	617	568	1,437	(221)
Preferred stock dividends accrued	(35)	(35)	(104)	(104)
Net income (loss) attributable to common stockholders	$ 582	$ 533	$ 1,333	$ (325)
Net income (loss) per share attributable to common stockholders:
Basic (in dollars per share)	$ 0.04	$ 0.04	$ 0.10	$ (0.03)
Diluted (in dollars per share)	$ 0.04	$ 0.04	$ 0.09	$ (0.03)
Weighted average common shares outstanding:
Basic (in shares)	13,062	12,798	13,009	12,781
Diluted (in shares)	14,955	14,076	14,901	12,781