Comment by ctcherry

People can vote sites both up and down, so assuming a decent number of people are participating you can can a general idea of what people think about a certain domain. In the case of something like ComputerWorld where some people don't care about the ad style, and some people do, it could have both up votes and down votes, each neutralizing the effect of the other so it wouldn't get as bad of a "rank" as sites where more people agree that they don't like it. Also, there is no import or export features so its still very much up to a user to checkout the domain and decide to block it or not, it's not making any decisions for you.