One, Audio books in a CD format cannot contain more than 75 minutes of content but audiocassettes can hold as much as 90 whole minutes (and, in many cases much more) of narration.
I agree you can have the entire audio book spread out in several CDs, but not many people like to carry around too many CDs.
So, while you might need just a few audiocassettes for a particular audio book, you will probably need many more CDs for that same audio book.
Two, most people don't like to spend extra cash buying CD audio books when they can get the same audio book cheaper in audiocassettes.
For example, while an unabridged version of "Harry Potter and the Goblet of Fire" on 12 audiotapes can be bought for just $31.96 on the Barnes & Noble website, the CD format from Barnes & Noble costs almost double that amount - exactly $55.96 for 17 sets of CDs!
Of course, its not that they want to rip you off - it's simply because it costs much more to produce CDs than it does to produce audiocassettes.
Three, when you turn off your CD player while listening to an audio book, you won't be able to resume from the particular spot you left off. With a cassette, you can begin from the exact same spot you left off.
With CDs it can be frustrating when driving because each time you turn off your car, it would mean restarting the audio book or trying to locate exactly where you stopped.
Of course there are modern and more advanced CD players that can now save your location when you turn off your car, thereby allowing you to resume at the exact same spot you left off.
This won't work when you turn off the car AND take out the CD. But it will work with an audiocassette!
Four, because audio books are mainly just narration, many users don't see why they should spend the extra money to buy CDs because of issues of recording quality when they can get near enough the same quality with audiocassettes.
Their argument is that if it was sound "quality" they wanted, they would go for audio books in CD formats, but sound quality is the same with audiocassettes and CDs when it comes to audio books.
In more succinct terms - "the voice of humans (without drums and other musical paraphernalia) has very little to gain from the depth and clarity that comes with digital recordings in CD format!
