Audiobooks...TV...Film...Translations...Videogames...all of these are called "subsidiary rights" and you can license your book into these formats. It's probably not an option today, but it can be down the road with some basic planning.

Learn how to write like the top 1% of authors: http://www.authorlevelup.com/fanclub

Listen to past episodes: http://www.authorlevelup.com/flash 

Watch my YouTube channel for writers: http://www.youtube.com/authorlevelup 

Read my books for writers: http://www.authorlevelup.com/books 

Check out my fiction: http://www.michaellaronn.com  and http://www.mlmcknight.com