According to an article on the Daily GalleyCat Blog 86 percent of Japanese high school students read cell phone novels.
The cell phone novel was born in 2002, when the author Yoshi wrote Deep Love: Ayu's Story for the cell phone. The book exploded in popularity, spawning print books, cartoons, and a film. The genre evolved, as authors published short novels in 70-word installments for the cell phone.
Ten of Japan's print bestsellers in 2007 were based on cell phone novels--successfully selling about 400,000 copies apiece. An article from Japan Today said that one company has released 40 titles that have sold 10 million copies.