That's still not making any money on the free software itself or from the users; that's just another "added cost service", and the persons paying for it, instea

That's still not making any money on the free software itself or from the users; that's just another "added cost service", and the persons paying for it, instead of being the user, is the one wanting to advertise to the user. I could just as easily use any search provider in Firefox that I want (and I regularly use search plugins for Wikipedia, IMDB, Python/PHP references, Thottbot, etc) in place of Google, and then Mozilla no longer makes money from me. However, that's not to say that your idea isn't an excellent one. I'm just pointing out that even if that idea had been implemented, Mark is still right. ;)