If it makes you feel any better, I've held the opinion for years now that ratings are broken across most services on the web. Jeff Bezos even acknowledged as much in a famous essay of his on how the distribution of one-to-five star ratings settle over time. Still, every new service sticks to the binary thumbs-up/down model or five-star. I'm sure you probably know the pitfalls of each, so good luck to you. I'm hoping you'll become the Disqus of ratings for every site. The analogy holds, interestingly, in my mind: comments had no consistency along UX or reputation before Disqus came along.