It was a pain in the ass. The porn industry developed 3rd party systems that would swap between merchant accounts on a whim. When people would put their credit card in, on the back end, it would try multiple accounts until it found one that would take the card and it was all integrated with a whole referral system [1] called NATS that was really sketchy software. It has been many years for me and seeing that they are still in business is kind of crazy really.
