Here is what I do not get about the iBook “model”.
I have a book about ready to go. It is a rework and upgrade of a book my wife and I have had on the college market since the mid 1990s. We have been moving our original print approach to a hybrid model combining a Primer and web content and the process is nearly complete. New additions are easy in comparison. A completely new structure is pretty much like starting over. We are planning on an inexpensive ($5-10 Primer and complimentary online content) approach. We hope this is a good deal for what is presently a $120 book.
Anyway, the Apple model and the development tool would be an easy implementation. However, here is the dilemma. It would require us to market the book for an exclusive market. University settings typically allow students a great deal of latitude in equipment purchases. The iPad, even if a great device, would be a second device for many students. At present, Amazon seems a much better choice. They promote various Kindles, but their focus is on the content and not the device. Any device can pretty much use Amazon content. The Apple model and the restrictive options for pursuing secondary paid opportunities do not make sense for academic content when students purchase their own devices and the expectation is that every student in the class will access the content.