Picture this: you see a soon-to-be-released-in-cinemas film is based on a book. For argument’s sake, let’s say it’s Cloud Atlas by David Mitchell. You think, “I like reading the book before I see the film”. You recently read Life of Pi and re-read The Hobbit in preparation for the films. So your train of thought chugs along until it reaches its station: “I’ll buy Cloud Atlas to read before the film”.