When you read a book on your Kindle, Amazon knows how fast you’re reading, where you got bored, and what you underlined. And publishers are using that data to try to write snappier books. We talked to WSJ reporter Alexandra Alter about how this works and whether it’s going to make every book more like the Da Vinci Code.

This is the kind of thing that is killing newspapers, like writing headlines for Google and generating tons of irrelevant, mediocre and banal content to drive pageviews. Well, apart from also being a blatant invasion of privacy.