Cool idea!

I think there are some ways to tie this into some general ideas for SN.

• Series posts: E-Books could be a version of a series post (which has already been proposed). Each page would be an entry in the series.
• Pay to read: I've seen this proposed by stackers a few times. Stackers could just generally be allowed to set a fee to read their posts.
• Sub-territories: e-books would make a great sub-territory of ~booksandarticles.

I know @cryotosensei has a couple of kids books already written and I'd love to be able to read them through SN.