Ad supported is a workable model, I agree.

The question if you would pay for it is directly because of Jason Cohen's post. If it's not worth paying for at some level, it's probably not a problem that's really screaming for a solution.

I'd pay for Google, for example. The fact that I don't have to pay for it is nice, but I'd cough up every month for it if it was a premium service, because it does something I absolutely need.