According to a study by Alan Sorensen at Stanford University, "In 1994, over 70 percent of total fiction sales were accounted for by a mere five authors." There's not much reason to think that things have changed. As Albert Greco of the Institute for Publishing Research puts it: "People who read fiction want to read hits written by known authors who are there year after year."

So we're experiencing the literary equivalent of a loss of biodiversity. All those people carrying around an 800-page novel looks like a great thing for American literacy, but it's as ominous as a Forbidden Forest with only one species of tree.