Have you noticed how on Rotten Tomatoes, when the movie is first released it usually has a higher positive score which normally dwindles over the days and weeks. Like the Hobbit, I have watched it's viewer ratings since last night and "mysteriously" the number of people who have watched it has remained the same 148,951. So all of a sudden Thursday evening comes around for most movies and there is a large number of people who afterwards log on Rotten Tomatoes to rate a movie that hasn't been released in most areas yet and a high number of people have given it a much better rating than it will likely have after it has run it's course. Then by Saturday afternoon, no one else has watched the movie and rated it on rotten tomatoes. So rotten tomatoes actually has something that skews movie ratings for the positive to incite people to want to go see them. Then after a time, it allows other people's rating to be registered and lower the movie viewer ratings.