Herrington’s memo pointed out that Walmart, Carrefour, Tesco, Metro AG, and Kroger were the world’s five largest retailers at the time. “All of them anchor their customer relationship in groceries,” he wrote. If Amazon’s retail business was going to grow to $ 400 billion in gross merchandise sales, it needed to transform a model based on infrequent shopping for relatively high-priced goods to more regular shopping for low-priced essentials. In other words, if the company was going to join the ranks of the biggest retailers, the S-team had to figure out a way to profitably sell supermarket items. If they didn’t, Amazon was going to be vulnerable to rivals who already enjoyed the shopping frequency and cost advantages of the grocery model.