I'm all for audio books, but I don't really listen to them myself.
For me the act of reading is as important, maybe more, than the actual contents of the book. The eye wandering over the letters in my own pace, re-reading certain #words and #sentences, the ability to mark #pages and write notes in the margins: it's unique to the written word and the book as a #physical object.
You can't feel the paper or smell the #ink with an audio book. It's intangible, and ethereal in a way.