When we imagine people without books, we think of villagers in places like Afghanistan. But many families in the United States have no children’s books at home. In some of the poorest areas of the country, it’s hard to find books for sale. A study of low-income neighborhoods in Philadelphia, for example, found a ratio of one book for sale for every 300 children. Tens of millions of poor Americans can’t afford to buy books at all. A nonprofit organization called First Book, is spearheading a new market mechanism that is delivering millions of new, high quality books to low-income children through thousands of nonprofit organizations and Title I schools. The First Book Marketplace is trying to do for publishing what micro-finance did for banking: crack open a vast potential market that is underserved at significant social cost.