Audio books are yet to replace the e-books but it will, eventually. The first e-bbok must have charged heavily; today, they are thrown everywhere in the Internet lanes for free of cost. I too hav dumped hundreds of e-books in the cyber space.
Similarly, the audio books were launched with great fanfare and were charged. Now, those first audio books are available for free of cost at Librophile.
Librophile, a website that compiles both free and paid audio books from LibriVox and Audible. Read more.