@JohnPhilpin I’m not sure if that model is what Brave does, it surely is what Medium does. I think I understood that the end plan for Brave is that the user decides who to give the BAT token to. Not sure if it works like that right now though.
An exchange to buy credits or tokens doesn’t need to be tied to advertisers in any way. I buy the tokens, pay with them, the publishers can sell them to get cash. It would be great if the exchange took as little fees as they could. Right now, token exchanges take quite a lot.