Unaudited Condensed Consolidated Statements of Operations - 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	$ 4,020	$ 2,369	$ 7,211	$ 4,632
Cost of revenue	1,590	926	2,874	1,778
Gross profit	2,430	1,443	4,337	2,854
Operating expenses:
Sales and marketing	46	431	458	845
Research and development	296	200	477	503
General and administrative	321	290	652	585
Operating income	1,767	522	2,750	921
Interest expense, net	(9)	(48)	(44)	(101)
Net income	1,758	474	2,706	820
Preferred stock dividends accrued	(35)	(35)	(69)	(69)
Net income attributable to common stockholders	$ 1,723	$ 439	$ 2,637	$ 751
Net income per share attributable to common stockholders:
Basic (in dollars per share)	$ 0.13	$ 0.03	$ 0.20	$ 0.06
Diluted (in dollars per share)	$ 0.11	$ 0.03	$ 0.17	$ 0.05
Weighted average common shares outstanding:
Basic (in shares)	13,523	13,017	13,466	12,982
Diluted (in shares)	15,371	14,791	15,314	14,756