The econometric results reveal that the reviews for the majority of the products have an asymmetric bimodal distribution.

etc. I thought everyone knew this, and it makes sense. You don't review something if you think it's "okay". You review it if you love it or hate it. Rottentomatoes probably has a bell curve because the professional reviewers review everything, whether they want to or not.

Also, the reviews on youtube are quite useful, and a three-or-less star average indicates that something is labeled incorrectly (for copyrighted material, tv shows, movies, videos, and the like).