PAPER IS BACK After years of seemingly unstoppable growth, e-book sales have started to slip, while paper has improbably bounced back. Digital book sales fell nearly 10 percent in 2015 from the previous year. Paperback sales grew by a healthy 16 percent, according to the Association of American Publishers, which tracks sales from more than 1,200 publishers.

GRAY DIGITAL Those who came of age with digital technology seem, surprisingly, to prefer paper to pixels. Young readers are less drawn to e-books. Only 13 percent of 18- to 24-year-olds primarily read e-books these days, compared with nearly 30 percent of 55- to 64-year-olds, according to a recent survey of 4,992 book buyers conducted by the Codex Group, a publishing consultancy.

READ IT ON THE PHONE Last year 15 percent of e-book buyers read their books primarily on smartphones, up from 6 percent in 2013, according to a survey of 6,000 people by Nielsen Books & Consumers. In that same period, Amazon’s dedicated e-reader, Kindle, seems to have fallen in popularity: 21 percent of e-book buyers said they read on Kindle e-readers in 2015, compared with 30 percent in 2013.