Some people just prefer to listen. I read well and I read quite quickly -- I don't know how many books I've physically read, but it's gotta be in the high hundreds at least -- but over the past ~10 years I've switched primarily to audiobooks. Rather than being something that I enjoy while I'm doing something else, I typically do something mindless with my hands (weave chainmail, cross stitch, sew) in order to give my full attention to the book.
Some audiobooks also seem to gain over the book; for instance, IMO, James Saxon's narration of "Blandings Castle" is truly excellent and gets out the most of Wodehouse.
