REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Net revenue	$ 109,110	$ 96,803
Brand Direct
Disaggregation of Revenue [Line Items]
Net revenue	61,228	56,179
Marketplace
Disaggregation of Revenue [Line Items]
Net revenue	58,806	49,259
Technology Solutions
Disaggregation of Revenue [Line Items]
Net revenue	2,336	2,017
Intercompany eliminations
Disaggregation of Revenue [Line Items]
Net revenue	(13,260)	(10,652)
Customer acquisition
Disaggregation of Revenue [Line Items]
Net revenue	105,165	91,350
Customer acquisition | Brand Direct
Disaggregation of Revenue [Line Items]
Net revenue	59,619	52,901
Customer acquisition | Marketplace
Disaggregation of Revenue [Line Items]
Net revenue	58,806	49,101
Customer acquisition | Technology Solutions
Disaggregation of Revenue [Line Items]
Net revenue	0	0
Customer acquisition | Intercompany eliminations
Disaggregation of Revenue [Line Items]
Net revenue	(13,260)	(10,652)
Managed services
Disaggregation of Revenue [Line Items]
Net revenue	3,119	3,946
Managed services | Brand Direct
Disaggregation of Revenue [Line Items]
Net revenue	1,609	3,278
Managed services | Marketplace
Disaggregation of Revenue [Line Items]
Net revenue	0	158
Managed services | Technology Solutions
Disaggregation of Revenue [Line Items]
Net revenue	1,510	510
Managed services | Intercompany eliminations
Disaggregation of Revenue [Line Items]
Net revenue	0	0
Software services
Disaggregation of Revenue [Line Items]
Net revenue	826	1,507
Software services | Brand Direct
Disaggregation of Revenue [Line Items]
Net revenue	0	0
Software services | Marketplace
Disaggregation of Revenue [Line Items]
Net revenue	0	0
Software services | Technology Solutions
Disaggregation of Revenue [Line Items]
Net revenue	826	1,507
Software services | Intercompany eliminations
Disaggregation of Revenue [Line Items]
Net revenue	$ 0	$ 0