I doubt the models sustainability a bit because I remember comparable models from the early days of Internet advertisement. You had to download a bar to you Desktop and then advertisements ran on it while you were using the computer (making the usable screen a bit smaller). That's not around anymore too, actually it vanished very quickly. I don't know why, probably the market just wasn't ripe for that kind of stuff, but there must be something why this hasn't been established in the past 10 years, because it's not too far away from a normal idea to have and technologically also not that sophisticated. But since I started hating Firefox recently, I will give this new browser a chance..
RE: Earning cryptocurrency using Brave and BAT