"Does this say something about the kind of people who own Kindles/read Dan Brown books or is it actually something as innocuous as pricing?"
I think it tells you something about the kind of people who buy books on Amazon, nothing else. I mean you can get Dan Brown's new book at Wal-mart for less than $15, but if you'd rather wait for it to ship (and possibly pay for that shipping), than stop off at the local Wally-World, that's your business.
Personally, if I want it now, and own a kindle, I'll download it. Otherwise, I'll drive to any local store and buy it on my way home from work. No reason to wait for the UPS guy to decide to deliver my book.