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BookSuggester

I own or have read...

Unsuggester takes "people who like this also like that" and turns it on its head. It analyzes the eighty-two million books LibraryThing members have recorded as owned or read, and comes back with books least likely to share a library with the book you suggest. The unsuggestions come from LibraryThing data, not from Amazon. LibraryThing also produces great suggestions.