I came across this blog post that explains how major exchanges set their fee schedules to promote liquidity:
http://blog.bitcointitan.com/post/25759461251/maximizing-liquidity-through-the-make-or-take-model
http://blog.bitcointitan.com/post/25759461251/maximizing-liquidity-through-the-make-or-take-model
Great article! Bitcointitan did all the research
I have nothing to add to what he wrote! I've been looking for this. This could bring a little bit more "sanity".