I certainly have to agree with the comments on impulse buying - there's nothing easier than that "One click" moment. Perhaps someone will write an app that would display your credit card balance before allowing you to click!
I also agree with the observation of how easy it is to stop or interrupt your reading to move on to another title. I have many partially read books on my Kindle. But then, I also have a pile of pbooks with bookmarks by my recliner.
I think the real key point of the article is the emphasis on increasing the availablility of titles - not only instant gratification with Whispernet ordering, but the vast sea of ebook titles out there. What we do with them, and how we deal with them, individually and as a society, remains to be seen.