In reception at the west London offices of Dunnhumby there are four clocks hanging on the wall, showing the time in London, Cincinnati, Seoul and Melbourne. They are there, says Martin Hayward, to impress upon visitors and staff how much the company, which specialises in consumer data, has grown over the past decade. "We could justify having Toronto, Paris, Cape Town and Shanghai up there too," he adds.

Drive to the head office of the supermarket chain Tesco in Cheshunt, a drab commuter town north of London, and you will see that the retailer, which owns most of Dunnhumby, also has a clock wall. This has 12 faces, telling the time from Seoul to Warsaw. Soon Los Angeles will be added; Delhi might be next.