to me, it's a good idea to always carry two sacks of something when you walk around. That way, if anybody says, Hey, can you give me a hand? You can say, Sorry, got these sacks.
I've heard that supermarkets waft bakery smells around the store to subconsciously encourage customers to buy bread. I can only guess that my local Costcutter supermarket is trying to encourage its customers to buy toilet rolls.