When something goes from one medium to another, it's because of two elements: 1. * It's popular! 2. * Producers like money! Moving something to a new medium is a way of breathing new life into an existing product which generates two things. New revenue from the fans, and new revenue from potential fans who for one reason or another never were into it in its original medium, but might get into it here. See also: In Name Only for the more extreme New Blood cases, or They Changed It, Now It Sucks and Pandering to the Base for the more extreme Old Guard cases.