Yesterday I was joking with the staff in 7/11 my wife bought some things and when she got to the checkout, they have all these special offers, she had a small drink so now she can swop it for a large one, Free, she also had a small bag of crisp ok now swop that one for a large packet, hey whats going on here farang no get special offers? only Thai get, they have this chart at the checkout with all these special offers get your wife to check it out, buy one get one or a bigger one,