Stock-based Compensation (Tables)

6 Months Ended

Jun. 30, 2017

Stock-based Compensation

Compensation costs related to stock-based awards

The following table summarizes compensation costs related to our stock-based awards (in thousands, except per share data):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2017		2016		2017		2016
Cost of revenue	$	7	$	5	$	15	$	10
Selling, general and administrative		252		213		508		413
Research and development		51		37		99		85
Total stock-based compensation		310		255		622		508
Tax effect on stock-based compensation		—		—		—		—
Net effect on net income	$	310	$	255	$	622	$	508

Weighted-average assumptions

	Three Months Ended		Six Months Ended
	June 30,		June 30,
	2017		2017
Expected term (in years)	—		5.9
Volatility	—	%	46.71	%
Expected dividend	—	%	—	%
Risk-free interest rate	—	%	2.08	%

Summary of stock option activity

The following table summarizes the stock option transactions during the three months ended June 30, 2017 (in thousands, except per share data):

				Weighted-
				average
		Weighted-		Remaining
	Number of	average		Contractual	Aggregate
	Options	Exercise		Life	Intrinsic
Stock Options	Outstanding	Price		(in years)	Value
Balance as of January 1, 2017	3,294	$	3.38	7.23	$	5,301
Granted	60		5.95
Exercised	(289)		3.06
Canceled and expired	(14)		2.18
Balance as of June 30, 2017	3,051	$	3.47	6.93	$	8,805
Options vested as of June 30, 2017 and unvested options expected to vest, net of forfeitures	2,997	$	3.46	6.90	$	8,690
Options exercisable as of June 30, 2017	1,677	$	3.35	5.58	$	5,054

Restricted stock awards

A summary of activity related to restricted stock awards for the six months ended June 30, 2017 is presented below (in thousands, except per share data):

		Weighted-Average
		Grant Date
Stock Awards	Shares	Fair Value
Non-vested as of January 1, 2017	325	$	3.27
Granted	26	$	6.80
Vested	(74)	$	3.22
Forfeited	—	$	—
Non-vested as of  June 30, 2017	277	$	3.62