I thought this was going to be "is an audio book really reading?" question.
I don't read the promotional stuff -- praise for this book or some other book in the series -- and I don't very often read the acknowlegments. I don't read prefaces and afterwards that are basically thanks and appreciation. I think they should be there, but I only look at them if I am curious about something in particular. Prefaces and afterwards that are actually part of the story, but separated from the main body for one reason or another, I read.
I feel like I'm somewhere between "read every word" and "occasionally skip stuff". I think I need to vote for "occasionally skip stuff", although strangely, I *feel* like I read everything. I didn't realize I was skipping so much!