A $100 Piece of Paper

So I went to the bookstore yesterday to buy a program for school. They handed me a small cardboard like piece of paper all nicely wrapped in plastic. I preceded to the checkout line where I swiped my card and signed away 100 dollars. Today I decided to download it. I opened it up fully expecting a nice cd rom of information to keep and then download to my computer. Then to my surprise there was nothing... it was just a fancy wrapped code. Seriously?