I originally posted that I thought books were exempt from charges, but then saw someone right below had already said (and with more certainty than me!).
Sorry, probably should have either left it there or deleted it entirely.
Oh OK, no worries. My comment went from many upvotes to several downvotes, because people assumed that you were saying that my information was redundant and should be removed. We got to experience a bit of a hive-mind on HN. :)
Saw just after posting that a good few other people already offered the same information.