It would seem that software that uses the tastes of large number of people to help suggest products based on your past experiences can significantly increase sales. If the technology is not implemented correctly or nut not implemented at all, it can potentially create problems.
Just ask Wal-Mart who suggested "Planet of the Apes" and "Ace Ventura: Pet Detective" as movies whenever customers ordered Martin Luther King, "I have a Dream." (article).
Back in 2000 a company called NetPerceptions was doing a great deal of innovative things in this market. They had a suggestion engine that seemed very useful. I wrote about them at least once. I think the bubble bursting may have killed them. When you go to their website, this is what you see:
Tornago Systems is now the fully licensed developer and reseller of the NetPerceptions NetP™7 product line. For more information or product support, contact Tornago.