The photocopy service provided by the library was a very vital one when I was a student. At that time there was no internet, and I got most of my reference materials from the library for my projects. As some reference materials could not be taken out of the library, thus when I needed to refer to some pages for the projects, I had to photocopy those pages.
The photocopier was accessed using a stored-value card. The card was made of paper with a magnetic strip at the back. The magnetic strip contained the value left in the card that was shown on the card reader. Each time a page was copied, the value would decrease. When it reached 0, the card could be discarded as there was no top-up service. I cannot remember how many photocopy cards I had bought during those days.