Unaudited Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue	$ 3,860	$ 2,665	$ 11,071	$ 7,296
Cost of revenue	1,465	967	4,339	2,744
Gross profit	2,395	1,698	6,732	4,552
Operating expenses:
Sales and marketing	356	466	813	1,311
Research and development	297	329	775	832
General and administrative	277	243	930	828
Operating income	1,465	660	4,214	1,581
Interest expense, net	(1)	(43)	(45)	(144)
Net income	1,464	617	4,169	1,437
Preferred stock dividends accrued	(35)	(35)	(104)	(104)
Net income attributable to common stockholders	$ 1,429	$ 582	$ 4,065	$ 1,333
Net income per share attributable to common stockholders: Basic (in dollars per share)	$ 0.11	$ 0.04	$ 0.30	$ 0.10
Net income per share attributable to common stockholders: Diluted (in dollars per share)	$ 0.09	$ 0.04	$ 0.27	$ 0.09
Weighted average common shares outstanding: Basic (in shares)	13,523	13,062	13,466	13,009
Weighted average common shares outstanding: Diluted (in shares)	15,371	14,955	15,314	14,901