Public libraries serve many roles in their communities, including the one they’re best known for: they ensure everyone can freely access books and other media, all without having to pay.

An unfortunate misconception that some have about this model is that libraries undercut book sales by loaning out free copies-but library staff, readers, and publishers have data and insights that show this simply isn’t true. Many publishers are also among the greatest fans and supporters of libraries because they know what an important part of the book and reading ecosystem libraries are.

A recent Twitter thread by librarian and author Hayley DeRoche breaks it down:

“Libraries have to pay for the MASSIVE number of books they purchase. There are public libraries that will purchase not just one but TEN or TWENTY copies of your book…. That’s a power buyer.”

Libraries frequently also buy additional copies of the same title over the years, since library books experience more wear and tear than the reads on your personal bookshelf. “We often *re-purchase* titles. We get boxes of new and replacement board books all the time, as well as juvenile titles that see a lot of use,” DeRoche shares.

Programs like library book clubs require libraries to invest in even greater numbers of copies; these activities also lead readers to discover new authors. “My experience as a librarian has been that particularly when it comes to book discussion groups, folks often say they wouldn’t have picked the book up on their own,” DeRoche explains. Borrowing a book for free often inspires readers to go out and buy more titles from the same author: “We facilitate multi-book purchases that readers would not make on their own.”

Libraries also help writers find new fans by hosting in-person and virtual author readings, sharing book lists on social media, curating book displays, and offering personalized recommendations to members of their communities. They play a crucial role in helping authors connect to new audiences, building buzz around their books that can in turn boost sales. “We are often making a purchase that a single reader would not make, even if they saw your book in the store and thought ‘hm,'” says DeRoche. “We put your book in readers’ hands, often creating lifelong author fans.”

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