I remember about ten years ago BP garages ran a promotion where you collected stickers and exchanged them for cds and videos ( I think you had to collect around 25, 1 for every £5 of fuel ).
Anyway my friend and I both worked part time in a BP garage and call it what you will ( stealing probably) aquired a vast amount of tokens.
We would take the cards with all our stickers in them to another Bp garage and swap them for cds then take them to John Menzies and exchange them for money ( we found out the cds that were £15 ).
What a nice little earner.