Yesterday CNBC aired a documentary called Supermarkets, Inc. You can read about it at this link. It was a very interesting documentary about how grocery stores do business, how they set up their stores in order to sell us stuff that we didn't even come to buy, how they order food, how long they have items such as bananas in their warehouse and so on.
It should be on again over the next month or so. If you notice it on your t.v. schedule, I recommend watching it. Anything we know about the grocery business helps us become more savvy shoppers.