This is one of biggest gripes with Netflix as well. Their percentage rating system just tells how close a title is to stuff you have already watched. The problem with this kind of recommender system is that you stay in a bubble and never see content that is a departure from what you normally watch. Sadly, this is the case with most applications today.

Coming back to the topic, Netflix sorely needs an actual rating system, either like IMDB or something built in-house.