Pret a Manger gives free coffee to some customers

Coffee and sandwich chains can be a great business to own if you can persuade your customers to go back day after day after day.

It's why they have loyalty schemes. Most of them have a card that they stamp, so that after 10 purchases you get a free drink or something else.

But the British chain - Pret a Manger, which has started expanding around the world - has a different idea.

It allows its staff to offer a free drink to whichever customer they want to. Not all the time of course, just occasionally.

But the chain's boss has told a British Newspaper this week it means that 28% of its customers have had, as some time or other, something free.

Rebecca Battman runs a brand consultancy and thinks it's a great idea.