
	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Cost of revenue	$	161	$	97	$	334	$	324
Sales and marketing	2,595		2,881		5,427		6,499
Research and development	8,447		7,978		17,907		17,765
General and administrative	4,386		6,683		10,497		14,622
Total stock-based compensation	$	15,589	$	17,639	$	34,165	$	39,210

Under the Company’s 2021 Equity Incentive Plan, as of June 30, 2024, 30.8 million shares of Class A common stock were authorized, of which 17.8 million shares of Class A common stock were available for future issuance. The number of shares reserved for issuance was increased in January 2024 pursuant to the evergreen provisions set forth in the 2021 Equity Incentive Plan.

Under the Company’s 2021 Employee Stock Purchase Plan (the “ESPP”), as of June 30, 2024, 3.7 million shares of Class A common stock were authorized. The number of shares reserved for issuance was increased in January 2024 pursuant to the evergreen provisions set forth in the ESPP.

The ESPP provides for concurrent six-month offering and purchase periods beginning February 15 and August 15 of each year. During the three months ended June 30, 2024, no shares of Class A common stock were purchased under the ESPP. During the six months ended June 30, 2024, 0.2 million shares of Class A common stock were purchased under the ESPP for an aggregate amount of $2.6 million. As of June 30, 2024, the Company recorded a liability of $1.2 million related to the accumulated payroll deductions, which are refundable to employees who withdraw from the ESPP. This amount is included within accrued expenses in the condensed consolidated balance sheets.


	Number of Options Outstanding	Weighted Average Exercise Price Per Share
Outstanding at December 31, 2023	5,159	$	2.27
Granted	—	—
Exercised	(337)	2.03
Forfeited/Canceled	(6)	2.00
Outstanding at June 30, 2024	4,816	$	2.29
Exercisable at June 30, 2024	4,791	$	2.29

On April 19, 2021, the Company granted the CEO Performance Award, which provided for a grant of 1.4 million RSUs consisting of five vesting tranches with a vesting schedule based upon achieving stock price targets as well as satisfying certain minimum service requirements. On December 21, 2023, the Company entered into the Cancellation Agreement with the CEO, which provided for the cancellation of the 1.4 million market-based RSUs included in the CEO Performance Award. As of the date of the Cancellation Agreement, none of the stock price targets set forth in the CEO Performance Award had been met and all of the RSUs were unvested. The cancellation resulted in an acceleration of $7.5 million in unrecognized stock-based compensation expense from future periods into the fourth quarter of 2023. Accordingly, the Company recorded no stock-based compensation expense related to the CEO Performance Award during the three and six months ended June 30, 2024. During the three and six months ended June 30, 2023, the Company recorded stock-based compensation expense of $1.5 million and $3.0 million, respectively, related to the CEO Performance Award.

For all RSUs, excluding the CEO Performance Award, the Company recorded stock-based compensation expense of $16.1 million and $34.7 million during the three and six months ended June 30, 2024, respectively, and $15.4 million and $34.6 million during the three and six months ended June 30, 2023, respectively.

As of June 30, 2024, total unrecognized stock-based compensation expense for unvested RSUs was $121.5 million, which is expected to be recognized over a weighted average period of 1.4 years. The Company had no outstanding performance-based RSUs as of June 30, 2024.