I've been playing with this for some time. You need 3 million monthly page views to qualify and I'm only at 2.5 million now.
My understanding is that if your site runs PHP, it's not too hard to implement as there are numerous free scripts offered from individuals. I'm running classic ASP, so I've had to start from scratch.
It seems like a great thing to be able to offer revenue sharing with your members, but my members aren't very computer savvy so I'm afraid they are going to have a hard time understanding all the implications. It sure beats me having to figure out how much everyone is earning and then paying them myself, though.