What Do You Call Those People Who Use Your Library?

I just started reading Listening to the Customer (2011) by Peter Hernon and Joseph R. Matthews.  The book opens with a discussion of what to call those people who use your library in some way - in person, online, etc.  I tend to call them users (I think a lot about our library webpage and its usability) or just students (or faculty or staff).  I understand the argument for "customer" but it feels so business world-y.  I know their tuition pays for the library and all, but it feels so strange to call them customers. 

What do you call them?  If you call them customers, does this change how you view them?