It's beach time, and you've probably already scanned a hundred lists of summer reads. Sadly overlooked is that other crucial literary category: the summer non-read, the book that you pick up, all full of ambition, at the beginning of June and put away, the bookmark now and forever halfway through chapter 1, on Labor Day. The classic of this genre is Stephen Hawking's "A Brief History of Time," widely called "the most unread book of all time."

How can we find today's greatest non-reads? Amazon's "Popular...