Dunnhumby, the global leader in customer data science, has released its fifth annual dunnhumby Retailer Preference Index (RPI) report, a nationwide study that analyses the $1 trillion U.S. grocery market. Amazon secured the first position, with H-E-B cementing second, Market Basket third and Wegman’s fourth position in the RPI report. A seamless Digital presence marked the highly ranked retailers as the top achievers. Grocers in the first quartile have long-term sales, growth, price, and higher emotional attachment with customers.