A startup idea: create a "dynamic pricing" adult payment processor that would try to undercut the competition by adjusting the amount they charge merchants depending on their chargeback history. You know, sort of like the insurance companies do (insurance is cheaper for those without claims). This way you differentiate between the true high risk merchants and those that are labeled as such just because they are adult.

Undercut the competition which charges upwards of 15%, using that process. Make a killing.