Say, you are in a situation where you have the ability to choose between several sellers of meat. You enter the market, and then you select a stall where the meat products seem decent. You buy something, and then you enjoy the product. The next week, what happens? Chances are, you would go back to the same stall. The probability of you going back to the same stall would be higher. Because somehow, you think that this stall will deliver the same standard that you enjoyed the previous time you have been there.
See, I suppose people who frequent supermarkets do not encounter this concept as much as people for example here in the Philippines. Unlike in North America, there are several places where one can procure one's produce here. There is the public market, which is just a conglomeration of several stalls, grouped into different types of things that they sell, and the sellers rent these stalls and sell their goods. So if you want fruit, just go to the fruit section and you can choose which stall to do business with. And after week after week of doing business, you develop a relationship with the seller, a relationship revolving around the concept of economic trust. With supermarkets, this is just impossible, as basically, the supermarket functions as a middleman for all the fruit sellers of the area. Of course, you can choose which supermarket to buy from, which would also revolve around economic trust, but also is influenced by other factors, such as convenience.
Here in the Philippines, this concept isn't just seen in the public market. Street sellers also manifest this. There are plenty of street sellers that sell a lot of things, from those interesting half-grown duck eggs, to dried and smoked fish, to soy bean curd, to bananas. If you wanted dried fish for example, you would wait until you hear a lady walking with a big pan on top of her head walks by, shouting Dried fish! Dried fish! You try her product, and if you like it, then the next time you want dried fish, you watch out for her, and recognize her voice, discriminating from the other ladies who shout the same thing. And as time passes by, even the seller will get to know how frequent you want to buy dried fish, and she would take the initiative to knock on your door shouting Dried fish! Dried fish!
Funny, this concept also is governed by Bayesian probabilities. How likely are you to buy something from the seller, is calculated by the likelihood of enjoyment you got from a previous encounter. Thus, if you have more data points of enjoyment from the past, then the likelihood that you will buy a product from the same seller is high. However, if you get a contradictory data point, say, you didn't experience enjoyment in a recent encounter, then the probability that you will stick to the same seller is going to decrease. In a supermarket, if you didn't like the fish you bought the last week, just hope that next week, they have something fresh.
Oh, and it applies to products that are not edible too. Car insurance, for example.