1 On entering a closed space, our natural impulse is to look left, but to scan and to move right – i.e. clockwise. So, a supermarket entrance will usually be on the left-hand side of the building. The lay-out of the supermarket is designed to carry customers clockwise, aisle by aisle, around the store.

2 Supermarkets mainly sell frozen, tinned and preserved foods. Still, displays of fruit, vegetables, flowers and houseplants are placed immediately inside the entrance to create an image of freshness, healthy eating and even “greenness”.

3 The commonest background colour in supermarkets is green.

4 Basic foods such as tea, coffee, bread, meat, sugar, eggs carry either low-profit or medium-profit margins. So, they are placed well apart and towards the back of the supermarket. On their way to these basic foods, customers are thereby “led” through as many aisles as possible, where tempting, higher-margin items are displayed.

5 Supermarkets regularly move certain foodstuffs in order to make customers change their habitual shopping patterns. In having to hunt down the new locations, customers are obliged to pay fresh attention to the whole store – and end up buying more.

6 Low-profit, regularly bought foods, tend to be stacked high in the narrower aisles. Here trolley speeds are at their maximum as customers grab left and right.

7 Wider aisles have the effect of slowing customers down, encouraging more attentive browsing, and boosting sales. The widest aisles contain the greatest proportion of high-margin foods.

8 Eye-level is buy-level. Eye-level shelves generate the highest sales. Usually they are reserved for big-selling branded goods, or for the supermarket’s own label, low-cost but higher-margin goods.

9 Chiller cabinets for displaying ready-meals and other “value-added” items which carry margins of up to 125 per cent are also placed at eye-level.

10 “Dump bins” are put at the end of an aisle, offering dented tins and date-elapsing foods. They are unofficially known as “shit bins” after the logic that anything they contain will sell.

11 Sales increase according to the “law of super-abundance”. For example, more packets of cornflakes will be bought from a 20ft long display than from a 15ft one. It is also true that customers buy more readily from a fully stocked store.

12 When confronted by such volume and variety of goods, customers’ blink-rate falls from the “normal” of 32 to around 14 a minute. At the checkout, however, reviewing what they’ve bought, their blink-rate shoots up to around 50 a minute.

13 The major supermarkets prefer debit cards to cheques and credit cards, because the instant a debit card has been electronically “slashed” at the checkout, the money is in the supermarket’s account.