RE: Shared monitization of the ad rev, great idea. I'd like to see it work. The only example I know of is a gone now service called ZenZoo that did this.
It sort of devolved into a multi level marketing thing with people trying to get other people to sign up so their share of ad rev would go up and you had log in a certain number of times a month or something.
Anyway, would be worth look up if anyone is thinking of trying this. I'd be in on an advertising, subtle, share.