Subway, the sandwich chain, has become the first operator to supply O2 Media’s location-based marketing service with scannable mobile vouchers, which sends a text message to a prospective customer when they are near one of its sites. The group said that the new technology, which works using “geo-fences”, will automatically send a MMS text to an O2 customers as soon as he or she enters a target area near to one of its c.1,500 UK sites. Customers can then take the text message into the Subway store and redeem the voucher there and then, without the need to print it out. The company said that it could use the system to directly track redemption figures from the offer to gauge its success. Simon Wallwork, marketing manager at Subway, said: "In conjunction with Subway's commitment to contactless payment, this advance demonstrates our dedication to providing an innovative consumer experience. This is the next step in the mobile evolution of Subway."