See, what's interesting to me is that the grandparent comment describes "50 Shades" as ~8 hours of reading. The zero-sum argument assumes that reading time is some fixed value for all people. I don't remember how long it took me to read "50 Shades," but it was significantly less than 8 hours, and couldn't have been more than an hour. (I'm not saying that to brag. It takes me a lot longer to do many other things than many other people. My only point is that the author of the article completely ignores throughput variability in his calculus.)