Just a simple suggestion. I have seen quite a few random drive by thread (star) ratings on ads. I would like to suggest that you change this from being anonymous to putting the rating members name on there. There are two major reasons but I am sure there are more.
1. If you are going to rate an ad you should rate it the same either way if your name is on there or not. If you think it's piss poor pricing or a deal and you rate it that way then have a nut sack and put your name on there.
2. Having names on ratings could eliminate competitive poor ratings.
3. If you have a douche who still rates ads improperly after adding the names to ratings, then I am sure some folks would sign up to be platinum just to pay the bastard back!