I don't know you can say Amazon is sacrificing any power. The Netflix prize isn't about better recommendations per se, rather its about predicting users movie r

I don't know you can say Amazon is sacrificing any power. The Netflix prize isn't about better recommendations per se, rather its about predicting users movie ratings. Its not clear predicting these ratings better will give better recommendations. I think most of the component algorithms in the Bell labs method provide fairly straight forward explanations - the best predictor is a nearest neighbour algorithm.