You guys are barking at all the wrong reasons why the movie wasn't a huge success. Sure, those things you guys said played a part (Although Avatar not really as it came out a month prior). The big reason was because marketing botched it and became the reason why future princess movies (Tangled, Frozen) had more unique names than the work they were based on. It was widely thought that simply because "princess" was in the title of the film, that automatically turned a subset of people off from caring to see the film, specifically males as they didn't show up for the movie like a Disney animation or Pixar film.