Non-cash compensation related to equity awards is included in the following line items in the accompanying consolidated statements of operations and comprehensive income (in thousands):


	Three Months Ended March 31,
	2024		2023
Cost of revenue	$	95	$	214
Selling and marketing expense	1,024		1,744
General and administrative expense	5,333		7,343
Product development	1,337		1,902
Restructuring and severance	—		71
Total non-cash compensation	$	7,789	$	11,274


	Number of Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value(a)
		(per option)		(in years)	(in thousands)
Options outstanding at January 1, 2024	734,775	$	150.74
Granted	—	—
Exercised	(54,103)	23.80
Forfeited	—	—
Expired	—	—
Options outstanding at March 31, 2024	680,672	160.83		3.74	$	3,199
Options exercisable at March 31, 2024	590,523	$	148.04	3.23	$	3,199

(a)The aggregate intrinsic value represents the total pre-tax intrinsic value (the difference between the Company's closing stock price of $42.34 on the last trading day of the quarter ended March 31, 2024 and the exercise price, multiplied by the number of shares covered by in-the-money options) that would have been received by the option holder had the option holder exercised these options on March 31, 2024. The intrinsic value changes based on the market value of the Company's common stock.


	Number of Options with Market Conditions	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value(a)
		(per option)		(in years)	(in thousands)
Options outstanding at January 1, 2024	718,438	$	229.02
Granted	—	—
Exercised	—	—
Forfeited	—	—
Expired	(19,126)	275.82
Options outstanding at March 31, 2024	699,312	227.74		4.39	$	—
Options exercisable at March 31, 2024	481,669	$	195.10	3.35	$	—

As of March 31, 2024, a maximum of 363,464 shares may be earned for achieving superior performance up to 167% of the remaining unvested target number of shares. As of March 31, 2024, no additional performance-based nonqualified stock options with a market condition had been earned.


	RSUs
	Number of Units	Weighted Average Grant Date Fair Value
		(per unit)
Nonvested at January 1, 2024	471,593	$	66.42
Granted	363,765	39.93
Vested	(194,992)	76.76
Forfeited	(17,931)	55.31
Nonvested at March 31, 2024	622,435	$	48.02


	RSUs with Market Conditions
	Number of Units	Weighted Average Grant Date Fair Value
		(per unit)
Nonvested at January 1, 2024	—	$	—
Granted (a)	69,000	35.83
Vested	—	—
Forfeited	—	—
Nonvested at March 31, 2024	69,000	$	35.83

(a)During the three months ended March 31, 2024, the Company granted RSUs with market conditions that will vest if the Company's 45 trading day average closing stock prices equals or exceeds certain price hurdles ($41.17, $52.94 and $64.70) during the performance period of March 1, 2024 to March 1, 2028. Upon achievement of each price hurdle, one-half of the awards will vest immediately, and the other half of the awards will vest on the first anniversary of the achievement date.

For purposes of determining stock-based compensation expense, the weighted average grant date fair value per share of the RSUs with market conditions was estimated using the Monte Carlo simulation model, which requires the use of various key assumptions.

(1)The expected term of RSUs with market conditions granted was calculated using a four-year performance period plus one year to account for the time-based vesting requirement.

(3)The risk-free interest rate is specific to the date of grant. The risk-free interest rate is based on U.S. Treasury yields for notes with comparable expected terms as the awards, in effect at the grant date.

(4)For all RSUs with market conditions granted, no dividends are expected to be paid over the contractual term of the stock options, resulting in a zero expected dividend rate.

In 2021, the Company implemented an employee stock purchase plan (“ESPP”), under which a total of 262,731 shares of the Company's common stock were reserved for issuance. As of March 31, 2024, 162,264 shares of common stock were available for issuance under the ESPP. The ESPP is a tax-qualified plan under Section 423 of the Internal Revenue Code. Under the terms of the ESPP, eligible employees are granted options to purchase shares of the Company's common stock at 85% of the lesser of (1) the fair market value at time of grant or (2) the fair market value at time of exercise. The offering periods and purchase periods are typically six-month periods ending on June 30 and December 31 of each year. No shares were issued under the ESPP during the three months ended March 31, 2024.

During the three months ended March 31, 2024 and 2023, the Company granted employee stock purchase rights to certain employees with a grant date fair value per share of $11.27 and $8.19, respectively, calculated using the Black-Scholes option pricing model. For purposes of determining stock-based compensation expense, the grant date fair value per share estimated using the Black-Scholes option pricing model required the use of the following key assumptions:


	Three Months Ended March 31,
	2024		2023
Expected term (1)	0.50 years		0.50 years
Expected dividend (2)	—		—
Expected volatility (3)	82	%	82%
Risk-free interest rate (4)	5.28	%	4.76%

(4)The risk-free interest rate is specific to the date of grant. The risk-free interest rate is based on U.S. Treasury yields for notes with comparable expected terms as the employee stock purchase rights, in effect at the grant date.