The amount of share-based compensation expense recognized by the Company by location in its statements of operations for the three months ended March 31, 2019 and 2018 is as follows (in thousands):

	Three Months ended March 31,
	2019		2018
Cost of revenues	$	10	$	4
Sales and marketing		204		54
General and administrative		218		55
Research and development		69		31
Total	$	501	$	144

In June 2018, the Company adopted the 2018 Equity Incentive Plan, or 2018 Plan, which authorized the issuance of up to 1.4 million shares, subject to an annual 4% evergreen increase, in the form of restricted stock, stock appreciation rights and stock options to the Company’s directors, employees and consultants. The amount and terms of grants are determined by the Company’s board of directors. To date, the Company has granted restricted stock units to one member of senior management and to an independent member of its board of directors as compensation for board service. All stock options granted to date have had exercise prices equal to the fair value, as determined by the closing price as reported by the Nasdaq Global Market, of the underlying common stock on the date of grant. The contractual term of stock options is up to 10 years, and stock options are exercisable in cash or as otherwise determined by the board of directors. Generally, stock options vest 25% upon the first anniversary of the date of grant and the remainder ratably monthly thereafter for 36 months. As of March 31, 2019, there were 1.5 million shares available for future issuance under the 2018 plan.

The following table summarizes the Company’s stock option activity for the three months ended March 31, 2019:

	Number of Shares under Option (in thousands)			Weighted- average Exercise Price per Option		Weighted- average Remaining Contractual Life (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2018		2,711		$	3.59
Granted		476		$	16.49
Exercised		(483	)	$	2.97
Forfeited		(34	)	$	9.88
Outstanding at March 31, 2019		2,670		$	5.92		7.9	$	26,014
Exercisable at March 31, 2019		1,286		$	2.14		6.7	$	16,859
Vested and expected to vest at March 31, 2019		2,670		$	5.92		7.9	$	26,014

The Company recognized share-based compensation expense related to stock options of $0.4 million and $0.1 million for the three months ended March 31, 2019 and March 31, 2018, respectively. As of March 31, 2019, there was $6.8 million of total unrecognized compensation cost related to non-vested stock options which the Company expects to recognize over a weighted-average period of 3.5 years. The weighted-average grant-date fair value of stock options granted during the three months ended March 31, 2019 was estimated at $8.93 per option. The total intrinsic value of stock options exercised during the three months ended March 31, 2019 was $6.8 million.

For the three months ended March 31, 2019, the grant-date fair value of stock options was estimated at the time of grant using the following weighted-average inputs and assumptions in the Black-Scholes option pricing model:

Estimated fair value of common stock	$	16.49
Exercise price	$	16.49
Expected term (in years)		6.1
Risk-free interest rate		2.5	%
Expected volatility		55.3	%
Dividend yield		0	%

The following table summarizes the Company’s restricted stock award and restricted stock unit activity for the three months ended March 31, 2019:

	Non-vested Restricted Stock Awards (in thousands)			Weighted- average Grant-date Fair Value		Non-vested Restricted Stock Units (in thousands)		Weighted- average Grant-date Fair Value
Non-vested at December 31, 2018		4		$	2.32		43	$	25.21
Granted		-		$	-		123	$	16.42
Vested		(3	)	$	2.32		-	$	-
Non-vested at March 31, 2019		1		$	2.32		166	$	18.69

The Company recognized approximately $0.1 million and minimal in share-based compensation expense related to restricted stock awards and restricted stock units during the three months ended March 31, 2019 and 2018, respectively. As of March 31, 2019, there was $2.8 million of unrecognized compensation cost related to non-vested restricted stock awards and restricted stock units, which the Company expects to recognize over a weighted-average period of 3.1 years. The total fair value at the vesting date of restricted stock awards and restricted stock units vested during the three months ended March 31, 2019 was $0.1 million.