> If Amazon is effectively a monopoly, so are Walmart, Costco, Target, and some others. I looked this up. Walmart is bigger than I thought! > Grocery sales ac

> If Amazon is effectively a monopoly, so are Walmart, Costco, Target, and some others. I looked this up. Walmart is bigger than I thought! > Grocery sales account for 56% of Walmart's total U.S. revenue, making it the country's largest grocer.