If you're one of the first 10 people to buy the book this week and send in your proof of purchase, you will get a free downloadable audio version of the book! (rachelheldevans.com)
The electronic and even audio versions of books can be placed on the market long before the print version. (computerworld.com)
Some authors create full production audio versions of their books for free, such as podcast novelists Scott Sigler, Tee Morris and Philippa Ballantine. (bookbuzzr.com)