STOCK-BASED COMPENSATION (Tables)

6 Months Ended

Jun. 30, 2021

Share-based Payment Arrangement [Abstract]

Allocation of recognized period costs

The following table summarizes the allocation of stock-based compensation in the condensed consolidated statements of operations (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2021		2020		2021
Delivery costs	$	357	$	521	$	532	$	830
Sales and marketing expense	2,567		3,655		3,836		6,087
Research and development expense	1,401		2,448		2,004		3,962
General and administration expense	4,783		6,713		6,861		9,706
Total stock-based compensation expense	$	9,108	$	13,337	$	13,233	$	20,585

Summary of common stock option activity

Options to purchase shares of common stock generally vest over four years and expire 10 years following the date of grant. The following table summarizes changes in common stock options:

	Shares (in thousands)	Weighted-Average Exercise Price		Weighted Average Contractual Life (in years)	Aggregate Intrinsic Value(1) (in thousands)
Options outstanding — December 31, 2020	513	$	23.91
Granted	—	—
Exercised	(80)	18.11			$	7,768
Forfeited	—	—
Canceled	—	—
Options outstanding — June 30, 2021	433	24.99		5.34	44,115
Exercisable — June 30, 2021	431	$	24.99	5.34	$	43,971

(1)For options exercised during the period, the aggregate intrinsic value represents the total pre-tax intrinsic value received by option holders based on the closing price of our common stock as reported on the Nasdaq Global Market on the exercise date. For options outstanding and exercisable at June 30, 2021, the aggregate intrinsic value represents the total pre-tax intrinsic value based on the $126.93 per share closing price of our common stock as reported on the Nasdaq Global Market on June 30, 2021, that would have been received by option holders had all in-the-money options been exercised on that date.

The following table summarizes changes in common stock options from the Dosh acquisition:

	Shares (in thousands)	Weighted-Average Exercise Price		Weighted Average Contractual Life (in years)	Aggregate Intrinsic Value (in thousands)(1)
Options outstanding — December 31, 2020	—	$	—
Assumed	104	3.06
Exercised	(4)	3.06			$	417
Forfeited	(29)	3.06
Canceled	—	—
Options outstanding — June 30, 2021	71	3.06		8.30	$	8,801
Exercisable — June 30, 2021	12	$	3.06	7.50	$	1,444

(1)For options exercised during the period, the aggregate intrinsic value represents the total pre-tax intrinsic value received by option holders based on the closing price of our common stock as reported on the Nasdaq Global Market on the exercise date. For options outstanding and exercisable at June 30, 2021, the aggregate intrinsic value represents the total pre-tax intrinsic value based on the $126.93 per share closing price of our common stock as reported on the Nasdaq Global Market on June 30, 2021, that would have been received by option holders had all in-the-money options been exercised on that date.

Schedule of stock options valuation assumptions

The Black-Scholes options pricing model is affected by the estimated fair value of our common stock as well as the following significant inputs:

	March 5, 2021
Value of Common Stock	$	128.06
Expected Term	7.0
Volatility	54.6		%
Risk-free interest rate	1.1		%
Exercise Price	$	3.06
Dividend Rate	—		%

Summary of RSU activity

We grant restricted stock units ("RSUs") to employees and our non-employee directors. The following table summarizes changes in RSUs, inclusive of performance-based RSUs:

	Shares (in thousands)	Weighted-Average Grant Date Fair Value		Weighted-Average Remaining Contractual Term (in years)	Unamortized Compensation Costs (in thousands)
Unvested — December 31, 2020	2,434	$	32.49
Granted	565	120.60
Vested	(303)	31.85
Forfeited	(108)	33.10
Unvested — June 30, 2021	2,588	$	51.76	2.86	$	108,964