I like the idea to adjust the percentage from a producer's perspective. In other words: play with it like the government plays with taxes in dCity.io. Pull it to 1 % for driving people to it. Push it to 10 % for covering some costs. Turn it to the user to choose or even turn it to the donor. Just don't stick to one of it, because you could drive away all the neysayers. ;-)

Why not add an option like: "choose who's playing with the fee throttle: developer, user, donor" and then I can chose to be fine with everything you do just by being asked. And soon you'll see in the back-end who you are dealing with and in what quantity. Welcome everyone! Just saying.