Most of the teen book collection occupies the wave wall, which has seating built in to encourage teens to stay and get lost in a book. An adjacent lounge with vending machines allows teens to socialize without bothering other patrons.
A Brief History of Book Vending Machines - There are lots of reasons why a white elephant technology doesn't catch on. Sometimes the technology is ahead of its time. In other cases, no amount of time can make a misguided technology useful or attractive. Then there's vending machines that sell books.