Stock-based compensation expense was allocated as follows:


	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Cost of revenues	$	90	$	46	$	214	$	81
Sales and marketing		157		70		332		136
Research and development		213		133		437		231
General and administrative		340		130		674		193
Total	$	800	$	379	$	1,657	$	641

For stock-based awards granted by the Company, stock-based compensation cost is measured at grant date based on the fair value of the award and is expensed over the requisite service period. Stock-based compensation capitalized as internally developed software was $24 and $50 for the three and six months ended June 30, 2022, respectively, and was $26 and $40 for the three and six months ended June 30, 2021, respectively.

There were no grants or exercises of stock options during the three and six months ended June 30, 2022 and 2021.

Compensation expense, net of forfeitures, is recognized ratably over the requisite service period. As of June 30, 2022, there was $66 of unrecognized compensation expense related to stock options, which is expected to be recognized over a weighted-average period of 0.3 years.

As of June 30, 2022, there was $4,889 of unrecognized compensation expense related to RSUs, which is expected to be recognized over a weighted-average period of 1.7 years. The Company uses the fair market value of the underlying common stock on the dates of grant to determine the fair value of RSUs.

The Company estimates the fair value of purchase rights under the 2013 ESPP using the Black-Scholes valuation model. The fair value of each purchase right under the 2013 ESPP is estimated on the date of grant using the Black-Scholes option valuation model and the straight-line attribution approach with assumptions substantially similar to those used for the valuation of stock option awards, with the exception of the expected life. The expected life is estimated to be six months, which is consistent with the purchase periods under the 2013 ESPP.