Suzie, who used to work at the Dallas Public Library, is wondering why librarians are being asked to refer to their patrons as customers. Does the word customer make consulting a library and borrowing books feel too much like a transaction? Eric Patridge, in his 1955 book The Concise Usage and Abusage, explains that you can have a patron of the arts, but not of a greengrocer or a bookmaker. What do you think people who use a library should be called? This is part of a complete episode.
Both seem inappropriate to me. I like calling them "readers" first, or perhaps "visitors." "Customers" or "patrons" promotes a money-changing atmosphere, even if patron is not defined as such. Sometimes that doesn't matter. It's the association people have with the word that should be considered, not some focus on proper grammar when assigning the identifier. If the idea is to welcome the masses, then offer a less stuffy appeal.