The question of ebooks as textbooks keeps coming up, along with questions of why are they not common yet. There are a number of factors that I see in the delay. First and foremost, at the college level, textbooks are chosen by the professor of record, and unless they are more ebook savvy, they will most likely be doing what they have done before and going with what they know. Why might they not know about ebooks and open source options, it could be that no one told them. A common way for instructors to find out about texts is a book representative shows up and helps explain the texts that they have for their class, there isn't usually anyone doing the same for opensource textbooks. Some of this may change quickly though, as both Florida's and Texas' Departments of Education have proposed changing to all digital texts by 2013-2015. If PK-12 schools do change to a fully digital format, then students showing up to colleges will have more of an expectation and experience skill set with digital textbooks. These states, but with state textbook adoption rules, are very powerful in influencing textbook design and publication.

As for students needed to interact with textbooks differently than novels, that is very true. To be an effective e-textbook, students will need to have the ability to interact with the texts to do things such as take margin notes, bookmark, underline, highlight, etc.

As a side note, I'm always a bit concerned when data about ebooks from the National Association of College Stores. I'm not surprised that they report that less than 3 percent of textbook sales are digital books, but what else could that mean? It doesn't necessarily include the rented ebooks, or ebooks that students get access to with printed text, it wouldn't include at all open source texts (such as I use with my undergraduate class) as there is no sales associated with such books.

As the e-book market explodes, publishers and educators debate why e-textbooks lag behind -- and what they should even look like. Campus Technology (3/1/11) http://campustechnology.com/Articles/2011/03/01/Can-Tech-Transcend-the-Textbook.aspx?Page=5&p=1