The paperback of “Fifty Shades of Grey” is exactly like the digital version except for this: If you hate the paperback, you can give it away or resell it. If you hate the e-book, you’re stuck with it.

Back in the ’90s, when Jeff Bezos was looking for a way into the wide world of the web, he analyzed over 20 different categories to decide which would be the “first best” place to start. He settled on ...