When is a reader most receptive to reading suggestions? Right when they’ve finished a book of course! That’s why printed books have information about other books by the same author, the first chapter of the next book in the series and similar material at the end as part of the back matter.
Back matter has existed pretty much as long as books have. This includes the appendix, glossary, index, and bibliography. Back matter for digital books needs to be optimized to serve the needs of the digital reader. An informal survey by @suw at http://chocolateandvodka.com/2013/04/10/what-do-readers-want-from-frontmatter-and-endmatter/ indicates the most popular endmatter desires were other books by the same author and some information about the author.
Digital back matter for ebooks is not constrained by having to proceed the publication; unlike print, digital back matter can be kept up to date with the release of new content. For instance, if an author publishes a sequel, that title could be included in previously published ebooks.
It’s easy to insert a page listing an author’s other books at the end of an ebook, but how do you keep that list up-to-date? What if you’ve developed a great recommendation system to do “if you liked Pride and Prejudice, you’ll like X”? (or maybe “if you hated...”!)
For this demo, we tested three reading EPUB environments, Readium, Readmill, and iBooks. We modified the Project Gutenberg EPUB version of Pride and Prejudice to include hooks and data to other books by Jane Austen.
Offline reading in Readium displays the resource embedded in the EPUB, similar to the iBooks version.