The sticker you can see in this image is the same size of a phone.
Small is half the size of a real phone - Half Size 4.05 X 7.89
Medium is the size of a real phone - Same Size 8.11 X 15.77
Large is twice the size of a real phone - Twice Size 16.22 X 31.54
Stickers can be placed on to posters, place mats, windows, menus pretty much any where you would like to get a consumer to get enter in to your campaign