If you are listening and not reading you may only hear what you understand verses looking things up, cross referencing and thinking about a word, sentence or paragraph.

I'm not a fan of audio books. When I read I do research. When I read the Fiat Standard I looked up Dr. Weston Price and found his book on nutrition. I read that, too. If you only listen to books you may miss a lot of material.

I do recommend Brian Tracy's Goals in audio and book form. Definitely will pump you up in business, sales and life strategy.