Sunday's Denver Post has a great article from staff writer Michael Booth on movie recommendation Web sites and how they work. They cover Netflix, What to Rent, Movie Lens, and Film Affinity.
""These systems don't really care who you are," Heckerman said. "They just compare your choices to other people's choices. A reputable system will throw out any personal information."
"The best way to get better picks, he said, is to crunch huge volumes of information. The more people that use a site and rate movies, the more accurate it gets for everyone." Read it