Like bookstores, libraries need to anticipate literary appetites. Unlike bookstores, libraries do not have a financial incentive to feed those appetites immediately. They have to balance civic missions and budget concerns with the imperative to put books in people’s hands. Sometimes, patrons have to wait. While bookstore best-seller lists monitor only what goes out, lists of the library’s most-circulated and most-requested books reveal not only which books readers want right now, but which they’re willing to wait for.