In case you missed it, stop thinking book or ebook and think, content and the many ways to sell it:
This kind of “format shifting,” in which a newspaper or magazine takes content that has already been published and reformats it for the Kindle or some other device, makes a lot of sense. That content can theoretically reach readers who might never have picked up the newspaper or magazine, or who missed it when it was first printed, or who want to read it in book form while sitting on their couch or at the beach rather than on a computer. And if the cost is low enough, they will be willing to pay for that convenience.
via What’s a book? It’s whatever you want it to be — Tech News and Analysis.