Maybe someone could start a service that automatically opts them out from arbitration clauses. Extra nice if it will send snail mail for the TOSes that require snail mail opt out.
But how much would you or others pay for such a service, on a monthly basis?
If a lot of places required snail mail, you could charge to send that. Offer to do digital opt out free as a sort of trial. If there aren't many snail mail opt outs, then I don't see a way to make money from it unless you have it as a loss leader for a legal services automation company.
It seems more like part of a more comprehensive bundle of services to me, not something you’d offer solo. Maybe bundle it with a service that takes EULAs and generates billet point lists of their main points?