There are over 42 million American adults, 20 percent of whom hold high school diplomas, who cannot read, as well as the 50 million who read at a fourth- or fifth-grade level. Nearly a third of the nation’s population is illiterate or barely literate. And their numbers are growing by an estimated 2 million a year. But even those who are supposedly literate retreat in huge numbers into this image-based existence. A third of high school graduates, along with 42 percent of college graduates, never read a book after they finish school. Eighty percent of the families in the United States last year did not buy a book.