IBooks subcategories?
It's possible I'm being dense but there doesn't seem to be a way to browse the iBookstore's subcategories. Just going to the "Nonfiction" category isn't particularly helpful if I want to browse a specific genre of nonfiction, for example. I figure this has to be an option given that all the books have subcategories you can see when you look at the book and it wouldn't make sense for that information to be there yet be useless. Am I missing something or is this functionality not there?
Thanks in advance,
Justin