Surge pricing comes to the supermarket

Online retailers are increasingly using your personal data to decide how much to charge you. And high-street shops are about to get in on the actIn 1861 a shopkeeper in Philadelphia revolutionised the retail industry. John Wanamaker, who opened his department store in a Quaker district of the city, introduced price tags for his goods, along with the high-minded slogan: “If everyone was equal before God, then everyone would be equal before price.” The practice caught on. Up until then