Boots are the UK’s leading pharmacist. Like most pharmacists, probably all around the world, they have expanded into selling other products. Unlike most, they have expanded on a huge scale into a bewildering array of non-medical products from which they derive most of their income. The larger branches of the retailing chain are “one stop shops” almost on the level of department stores.

On a recent visit, your contributor noted a tiny detail which sums up the secret of Boots’ success.

The real reason for the visit was the need for a little oil for a very old electric razor. As turned out, Boots had none – the modern fashion is, of course, to replace electrical goods rather than to maintain them – but the genius of Boots is that, whatever the reason for the initial visit, it is hard to leave the shop without buying something else.

In particular, it may just have been an oversight, but is more likely the mark of a brilliant sales manager, that there was, in the middle of the shaver supplies stand, a display of cheap black retractable umbrellas.

Retractable umbrellas? What possible link can there be between shaver supplies and retractable umbrellas?

This and only this: who buys them? Most electrical shaver products are bought by men – and men also buy most black retractable umbrellas.

At least they do in rain swept Britain. What is more, the rate of attrition for retractable umbrellas – between absent-mindedly leaving them behind at every other meeting and having them blown apart by the unpredictable British wind – is very high. Rare is the man who goes shopping with the deliberate intention of buying a retractable umbrella. Rarer still is the man who, seeing one immediately in front of his eyes at a cheap price when he is spending money anyway, could not do with a new one.

Significantly, the umbrella display in the razor stand was half empty.

The secret of marketing success is very simple. Find out who your customers are and whatever it might be that they will buy – then put it right in front of them at the very moment they are already spending money.