I have a slightly different topic on the subject of e-reading. I assign my students a reading in the traditional text and then have them read the same text on-line complete with ads, hyperlinks, etc.. After they have completed both readings, we discuss the experience. I have found that most students prefer the hard-copy over the digital because they find e-reading more distracting. While the notion of extending the subject through peripherary materials sounds inviting, it requires a greater amount of discipline on the part of the reader. Many students found themselves "Six degrees of Kevin Bacon-ing" their original reading and wasting a lot of time on secondary or non-related readings.
I agree - this is an issue - the digital siren song. Distraction of the digital environment. As soon as you go online there are so many other temptations. It is such an issue, not only for education, but for all aspects of digital life. It is so easy to get off the path.
That said, I also wonder if sometimes off the path is a good thing? I wonder if some of those distractions might provide pathways to deeper learning resources & opportunities for some students who want to go deeper than the course material might take them? Wouldn't it be great if that recommendation engine on YouTube would actually recommend additional resources that matched closely with the video they were asigned to view and that was the path that students took, instead of the path to Facebook?
I know it is a rather idealistic & naive view in a world where we compete with base instincts that value novel and new, but I know personally I have often found great resources that I stumble upon more through serendipity than design. Of course, i have often gone down many a rabbit hole as well...
I was also thinking that this is one of the reasons why I love my Kindle device vs my tablet for reading. It is a dedicated reader that removes many of those distractions. When reading on my Kindle, I am focused on the text and not tempted to check email, Facebook, and head off in other directions.