It seems there's a rule that if a genre television or movie series has a big fanbase, then tie-in novels will soon follow. Once the series has run its course, all media tie-ins come to an end. There are a few exceptions, such as Star Trek and Star Wars. The Star Trek franchise has been kicking out novelizations since 1967, and the first original novel, Mission to Horatius, came out one year later. To date, there have been over 850 Star Trek books published.