I think the arbitrage opportunity isn’t nearly as large as people imagine. Payment processors aren’t run by ideological zealots who refuse certain transactions on moral grounds. On the contrary, they are ruthless capitalists who’d love to get a slice of any and every multibillion dollar market under the sun.

I’m sure actuaries at MasterCard ran the numbers and found that the risk of accepting payments for live adult content (e.g. high level of chargebacks, extreme legal consequences for processing payments for blatantly illegal material, e.g. child pornography, that’s hard to filter out owing to the transient nature of live streams) far outweighed the benefits. And if you’ll excuse my appeal to authority, I assume those actuaries are correct, given the amount of money such a profit-focused company is walking away from.