It's hardly buried: it's mentioned in the description of the app, it's mentioned inside the app when you "publish", it's mentioned in the help file for the app, and it appears, in boldface letters, as an "IMPORTANT NOTE", at the _beginning_ of the EULA.

Also worth mentioning: the economics of K–12 textbook publishing are very different than mass-market publishing: essentially 100% of sales are volume purchases by educational institutions who are already accustomed to distributing materials to students.

This is Apple's proposed alternative to publishers bundling interactive content with expensive textbooks (probably "free" if available on the App Store), and the value proposition is wide exposure, lower infrastructure costs, and no used textbook market to undercut profits in exchange for "a la carte" distribution of individual "unbundled" books and a unit price cap.

In other words, it really is an attempt to apply much of the "iTunes business model" to textbook publishing, and it'll be quite interesting to see how it works out.