New poster here. High risk merchant accounts are typically aggregated with very low chargeback-history clients, to spread the risk. High risk merchant guys who run 5 % typically have a very liberal refund policy, and don't hit 5%.
High risk is simply a category of merchant who historically isn't in business very long, usually 2-5 years at a stretch. Adult is high risk because of the intial Rebill shedding of clients. Merchants who have very high chargebacks on first time customers usually go ACH or Check-21, then migrate the rebill clients who pay onto credit card.
I do alternative payment, ACh/Ch21, as well as high risk credit card accounts, and have been doing so for 10 years. Ask me what you would like to know. I DO DEAL WITH MERCHANTS BELOW 50K per month transaction volume.