 The court held that the differences in form between "The SAT" and "Seinfeld" and the lack of transformative purpose made the book a derivative work in a derivative market.Because the SAT was the only "Seinfeld" trivia book in existence, it completely substituted this derivative market for the show.The court further reasoned that even though Castle Rock did not intend to enter the trivia book market, the existence of "The SAT" effectively usurped its right to do so.