It's a tricky one. If you buy a broom and it is a good broom you will give it a review of 10. But where you are expressing a personal preference, shouldn't 10 be reserved for the best thing you have every seen? And 1 for the worst (of course there is never a zero). Then your votes would average out at 5. But folks are never going to get that idea, which is why these sites will never work.