I happen to be working on this right now http://browsercoin.com, if anybody is interested in beta testing it out, my email is in my profile.

> Extensions face API and performance limits. Our own browser lets us put our best foot forward on speed and deep integration of private ad-tech. We may do extensions if our users find themselves browsing in other browsers often.

Basically, their FAQ answer is debatable because the Chrome API is more than enough to support a Patreonesque model, if you have uBlock and other privacy focused extension, you don't even need to download a heavy browser client.

Hence the name BrowserCoin, I'd be open to feedbacks on what you would like to see happen with it.