*The Big Read* Tesco launched its iconic Clubcard 30 years ago, helping it storm ahead of rivals, until it eventually cornered nearly a third of the grocery market. But international rivals are beating it on price, and domestic rivals are catching up with customer data and loyalty. So what comes next for Britain’s beloved supermarket? In our latest Big Read, Michael Fahy explores the foundations of Tesco’s success, whether or not it can maintain its grip and if the shares still offer value. Find out more here: *https://on.ft.com/42yhquw*