Stock-based Compensation (Q3) (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2021

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Schedule of Class P Unit Activities

A summary of the Class P Unit activity for the nine months ended September 30, 2021 is as follows:

	Number of Units
Outstanding Class A-3 and Class B Units, December 31, 2020		274,816
Repurchases		(8,279	)
Cancellations		(4,288	)
Outstanding Class A-3 and Class B Units, June 15, 2021 (Pre-Business Combination)		262,249
Class A-3 Units outstanding exchanged for Class A Units in connection with the Business Combination		(53,333	)
Recapitalization in connection with the Business Combination		25,687,126
Outstanding Class P Units, June 16, 2021		25,896,042
Cancellations		(216,920	)
Outstanding Class P Units, September 30, 2021		25,679,122
Vested, September 30, 2021		23,197,454

The following presents issuances of Class A-3 and Class B Units during the years ended December 31, 2020, 2019 and 2018:

Outstanding at December 31, 2017	252,241
Granted	44,125
Repurchase	(12,391	)
Cancellations	(38,604	)
Outstanding at December 31, 2018	245,371
Granted	25,990
Cancellations	(7,284	)
Outstanding at December 31, 2019	264,077
Granted	14,250
Repurchase	(1,900	)
Cancellations	(1,611	)
Outstanding at December 31, 2020	274,816
Vested as of December 31, 2019	207,398
Vested as of December 31, 2020	234,114

Schedule of Restricted Stock Units Activity

A summary of the restricted stock unit (“RSU”) activity for the nine months ended September 30, 2021 is as follows:

	Number of RSUs			Weighted-average Grant Date Fair Value
Non-vested at December 31, 2020		—		$	—
Granted		4,112,855		$	13.66
Vested		(242,600	)	$	13.70
Forfeited		(11,310	)	$	13.70
Non-vested at September 30, 2021		3,858,945		$	13.66

Schedule of Stock-based Payment Arrangement

The Company recorded stock-based compensation cost related to the Class P Units and RSUs in the following expense categories on the accompanying condensed consolidated statements of income (in thousands):

	Three Months Ended September 30, 2021		Nine Months Ended September 30, 2021
Sales and marketing	$	689	$	4,515
Product development		1,865		3,859
General and administrative		1,638		15,251
Total stock-based compensation expense		4,192		23,625
Amount capitalized to software development		695		695
Total stock-based compensation cost	$	4,887	$	24,320