Air Port Library

A library in the air port whats not to love?  Travelers who are always on the go could sign up for a library card and borrow books, movies or CD's in Denver and then return materials in Chicago when they land.  You could have a airline specific libraries so it would make it easy to shuffle books back and forth.  It might also require a small fee to run efficiently.

Question:

How frequently would you have to travel before you think a library like the one above would be convenient?