We used to get these only at the pictures. The ladies with the trays around their necks would be 'lit up' in the aisles at either side of the screen so you could find them - all part of the experience in the 50's and 60's.
Green Shield stamps. My mum bought these in the early 70s, to 'save up' to buy things for our home. I remember seeing books and books of them. (This pin has been repinned almost every day since I first posted it!)