To me this seems like it would suffer from a chicken and egg sort of issue. To expand, this is useful to me as a consumer if I could install it and browse the web ad and guilt free, as well as having access to pay-walled content with my Atri subscription essentially paying for it. As a content provider, I'm only going to want to provide this avenue of "subscription" if it nets more money than my current method of monetization of my content. By the looks of it, this is trying to recruit users first, but what value is a user being provided for the $30 over 3 months other than being included in an artificially limited experiment?
edit: To be clear, I like the idea, and I think something needs to be tried in order for something to work. These are just my initial skeptical criticisms.