Many members of the book industry are engaged in different ways to support literacy efforts, and one strategy that continues to gain traction is selling used books to strengthen literacy programs.

One of the biggest literacy supporters, 14-year-old Better World Books, which was started by three Notre Dame graduates to sell used textbooks online, has donated 20.5 million books and raised nearly $23.8 million for literacy groups and libraries to date. Doing good is so interwoven into the Better World mission that in 2006, the online retailer, which also has a bricks-and-mortar bookstore in Goshen, Ind., became one of the first B corporations (a class of for-profit social ventures). In 2011, Better World made a commitment to donate one book for every book it sold.

“We’ve created a literary ecosystem,” said Diane Maier, director of global marketing and sales support at Better World. She pointed to the company’s partnerships with Books for Africa, which ships and distributes books for children in Africa; the National Center for Families Learning, which helps adults and children learn together; and Room to Read, which is focused on literacy in Asia and Africa. Better World also donates the books it can’t sell online to other literary, library, and education initiatives in the U.S. and around the world.

Earlier this year, Better World acquired a bookmobile, which operates out of its Mishawaka, Ind., distribution center. Rather than sell books, the bookmobile, which holds up to 3,500 books, gives books away two or three times per month at events within driving distance of the distribution center. Better World also makes donations through its other facilities. To celebrate World Book Day last April 23, the company made 25,000 free books available at its Reno, Nev., location.

Twelve-year-old Discover Books, which claims to be the largest used bookseller on Amazon, is based in Baltimore and is a for-profit company. But it, too, has donated millions of books to schools and nonprofits. “For the past eight years, we’ve made a commitment to give books to charities instead of recycling,” said Tyler Hincy, v-p of supply. “We have such a need. It’s mind-boggling that kids don’t have books.” Like other large online retailers, Discover places the books that it collects on a conveyor belt and scans them—10 million books a month—to decide which titles are salable and which should be donated or recycled. Because of Discover’s network of 12 warehouses across the country and in Vancouver, B.C., the company not only donates books but handles their delivery.

In 2006, Stacy Ratner launched nonprofit Open Books, a Chicago-based used bookstore and literacy organization, in the basement of her home. Over the past 10 years the group, which offers literacy enrichment programs for grades K–12, has grown and includes two stores: its flagship store with 50,000 used books in the West Loop, and a warehouse store in Pilsen, which primarily serves college students and educators. Open Books was named Chicago Magazine’s Readers’ Choice Best Bookstore 2015 and founder Ratner was a 2015 Chicagoan of the Year.

Open Books has five drop boxes throughout the city and suburbs, as well as a bookmobile, which picks up donations four times a week and has a one-month waiting list for pickups. “Access to books is key to accomplishing our mission,” said executive director Tim O’Brien. Last year Open Books donated more than 130,000 used books to public schools, the Ronald McDonald House, and other nonprofits. Between the stores and the sale of overflow books on AbeBooks, Alibris, and Amazon, Open Books is able to raise 70% of the revenue it needs to support the organization and its reading and writing programs, some of which take place in the schools, such as Reading Buddies, and its bookstores, such as Publishing Academy for young novelists.

Thirty-three-year-old Project: LEARN (Let Every Adult Read Now), which focuses on adult literacy, decided to start a used bookstore in December 2007 to create a much-needed new revenue stream. Then under the executive directorship of Linda Smalley, the organization set up three Bookshelf stores and tutoring centers in Medina, Brunswick, and Wadsworth, Ohio, which now provide 60% of the revenue the organization needs for its mission. Not only do the stores provide a steady cash flow—a plus for any nonprofit, as current executive director Karla Robinson pointed out—but the stores have also brought Project: LEARN closer to the adults they help and serve as the organization’s face to the community.

More than 100 volunteers work one shift a week at Bookshelf and sort the store’s donated books, and another 130 volunteers help with tutoring. Each store stocks a distinctive inventory, and books that can’t be sold go to a juvenile detention center, a jail, and a local cancer center. This spring Project: LEARN began partnering with an organization in Dayton, Ohio, to sell textbooks and obscure titles online. “Everybody thinks it’s easy to earn money online,” Robinson said. “But that’s not the case.” What makes the Bookshelf locations work in addition to volunteer labor is the ability to sell books at a flat rate.

After hearing Smalley give a presentation about how successful Bookshelf has been, former bookseller Travis DiNicola, executive director of 32-year-old Indy Reads, an adult-literacy program in Indianapolis, Ind., convinced his board to add a used bookstore, Indy Reads Books. It took another three years to open the 2,600-sq.-ft. store in 2012. “The great thing,” DiNicola said, “is that the bookstore has sustained itself.”

Indy Reads Books provides affordable books—most are priced between $2 and $5, and a wall of children’s books features titles that sell for $1 apiece—and a space for tutors to meet with their students. The store also serves as a gallery for local artists and offers events. “People really love [the store],” DiNicola said. “They love the mission and keep bringing us stuff.” The literary community has gotten behind the store in other ways. In 2014 Indy Reads published Indy Writes, a collection of fiction and nonfiction by local writers, including John Green, Ben Winters, Dan Wakefield, and puzzle guru Will Shortz.