For example, in adult
fiction 42 % are from indie publishers and 77 % are
bought online, compared to 14 % of
juvenile fiction from indie publisher and 48 %
bought online.
Most of the big success in Amazon based publishing seems to be with Adult genre
fiction and I've heard people comment that kids still learn about books from librarians, teachers etc... and don't make
buying decisions and therefore don't expect
juvenile fiction to work too well for self publishing.