I've been saying this is exactly and the only sort of thing blockchain might be able to solve. Absolutely prove you bought a thing. Only question is how to get

I've been saying this is exactly and the only sort of thing blockchain might be able to solve. Absolutely prove you bought a thing. Only question is how to get another service to care to respect that. Maybe prove Y% of your X purchase went to the rights holder. So you can only be charged for Z-Y to get that same thing from another service.