The most supermarkets work following the so-called law of the right hand, when the movement of visitors is organized counterclockwise. In this case, the buyer, moving around the store, turns left all the time, and his eyes often falls into the middle of right wall. In this place the so-called golden shelves are located, and on them - the most expensive products or “best before date” products.
We all know the old trick: 0.99 always seems much smaller than 1.0. Subconsciously penny grows to giant size savings. In the same direction fatty crossed the old price works, often written in a smaller font, and dedicated new ones. Your brain processes this information as an image, rather than as an arithmetic problem. And in the end you take not the desired thing to "save."
Perhaps it is inevitable. Each parent will have to go through a rite of passage: to go to the store with your child, and bear all his whims, requests for buying chocolates, new cereal, candies, etc... You are lucky if it would cost you only tears, but real hysteria wallowing on the floor and wild cries are not excluded.
Have you ever paid attention to that all the expensive items are on the middle shelf of the counter, just at the height of your eyes? This is done so that you first saw the most expensive commodity. The following is a calculation of the psychology that you have decided that the goods on the shelves that are higher or lower, are less quality (although usually it is not so.)
In the supermarket the so-called related products are always placed next to the main. Next to the beer - chips or bags with dried fish, next to the cookies - juices or sodas; next to shirts - ties, etc. There are all for you to buy more.