In latest retail tech, Carrefour lights have eyes

The new technology being trailed by French retailer Carrefour tracks your movements and beams data to your smartphone via light pulses undetectable to the eye, to guide you to the right shelves for tailored special offers. It is the latest attempt to combine the online and real-world shopping experience, regarded as the holy grail for the industry at the moment. As part of a new loyalty scheme launched last month, for example, Britain's Marks and Spencer is sending promotional text messages to s