Print power buyers make up 22 percent of the overall print book-buying population, and they drive 53 percent of print book purchases overall.

Meanwhile, e-book power buyers make up 35 percent of the overall e-book buying population, but they drive 60 percent of overall e-book purchases. In other words, about a third of the overall buyers drive two-thirds of overall purchases. Casual e-book buyers “are not pulling their weight” compared with casual print book buyers, Gallagher said.

via E-Book Bummer: Growth Slower Than Thought—‘Incremental, Not Exponential’ | mocoNews.