Swedish company Bluegrid has come up with a way of making mobile phones simulate loyalty cards exactly. The technology is being used by airline SAS and has just been purchased by an unnamed UK retailer with 500 outlets. Chief executive Christopher Engman says: "Usually consumers leave their loyalty cards at home. Recent surveys have shown that most Swedish consumers use just two out of the ten cards they have. Increasingly, young consumers don’t carry a wallet at all – just a bank card, some cash and a mobile phone."

He points to other advantages: "You don’t need to send out sign-up packs, which typically cost 10 euros. There are almost no set-up costs this way. The consumer can set up a loyalty card by simply phoning a number after seeing an advertisement. And new offers can be sent by SMS text message – that is far cheaper than mailing a brochure."

But do consumers want to receive spam?  Engman acknowledges the potential problem and says: "We advise our customers to only send out messages with real value attached – money-off coupons, special offers that are really worth something."