Children's books were the fastest-growing segment of the industry in 2011, increasing 12%, to $2.78 billion, according to BookStats.
Other surprising facts about children's literature are:
50+ million =
Number of copies of "The Hunger Games" trilogy that are now in print in the United States.
Bestselling author for children ages 8 to 16 in 2011. He has sold more than 22 million middle grade and young adult books worldwide.
Number of children under school age whom Stephenie Meyer was mothering while she wrote "Twilight":
three — all of them boys.