Amazon has filed a patent that describes how to take the obvious, heretofore un-stepped step of filling ebooks with contextual, timely advertising. Whether it would mean free, discounted, or tiered-price books (or none of the above) it's an interesting idea.
As you can see from the diagram above, there's nothing terribly complex about the proposed system: banner ads sit atop and beside select pages, and can be catered to suit the page's content, the book's subject matter, or simply the reader's assume demographic. It's a bit like, you know, how the entire internet works, except in a book, so it gets a patent I guess?
A second, similar filing describes pretty much the same deal, this time for on-demand printed books.
Given how simple the patent is, and how eager Amazon seems to make a little extra scratch from their reader, the real question about the possibility of ebook ads is how they'd fit into the Kindle ecosystem. On this, the patent offers a few clues:
Including advertising and/or related content with on-demand printed content may prove advantageous to a consumer. For example, a lower price may be offered to a consumer regarding a request for on-demand printed content if the consumer is willing to accept advertising in the printed content
This is a "for example" section in a patent application, which is about as far away from binding as you can get. But it's interesting to think: an ebook advertising rollout—at least, a simple one, with static, predetermined ads—would be as simple as adding new listings to the Kindle Store. [Register]