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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Concentration Risk [Line Items]
Advertising costs	$ 16,229	$ 12,807	$ 39,528	$ 34,354
Accounts Receivable \| Customer Concentration Risk \| Apple
Concentration Risk [Line Items]
Concentration risk (in percent)			67.20%		56.20%
Accounts Receivable \| Customer Concentration Risk \| Google
Concentration Risk [Line Items]
Concentration risk (in percent)			18.10%		27.50%
Accounts Receivable \| Customer Concentration Risk \| Stripe
Concentration Risk [Line Items]
Concentration risk (in percent)			10.20%
Revenue from Contract with Customer Benchmark \| Customer Concentration Risk \| Apple
Concentration Risk [Line Items]
Concentration risk (in percent)	59.30%	55.20%	58.30%	53.40%
Revenue from Contract with Customer Benchmark \| Customer Concentration Risk \| Google
Concentration Risk [Line Items]
Concentration risk (in percent)	24.90%	27.70%	25.70%	28.40%
Revenue from Contract with Customer Benchmark \| Customer Concentration Risk \| Stripe
Concentration Risk [Line Items]
Concentration risk (in percent)	12.60%		12.10%