Just as the arrival of self-service shelving transformed the physical layout of shops in the past century, online shopping will do so in this one. Already we've seen internet shopping become a competitor to bricks-and-mortar stores. Now it will reshape them.

At Wal-Mart, for instance, more than 40 per cent of the online orders on the retailer's website are sent for pick-up at a local store, as customers seek to avoid the costs and timing uncertainties of home delivery. In response, the retailer is testing drive-through pick-up options and redesigning stores to include pick-up counters at the front. In the UK, Tesco has similar arrangements (though no drive-throughs yet).

Sears Holdings has taken things even further at a pilot store outside Chicago called MyGofer, where four-fifths of the floor space is backroom storage, and one-fifth open to customers who can pick up pre-ordered items, or use computer terminals to order what they want in store. Sound a lot like Argos? Here's the twist: Kmart is also trying to persuade other retailers to use its stores as a central pick-up location for goods ordered online. Retail industry analysts speculate that even the purely online Amazon might eventually want to set up pick-up locations.