After years of investment in its technology and stores, Walmart has indisputably emerged as a strong No. 2 to Amazon in U.S. e-commerce, with sales up 37% last year. But as the initial weeks of the novel coronavirus pandemic have shown, Walmart’s 4,600 U.S. stores have proved to be an effective weapon by allowing curbside pickup for online orders at a time shoppers want to limit time in stores—but still want their orders quickly. That sentiment is not likely to change anytime soon. Walmart Inc.’s Sam’s Club is finding renewed energy, too. Walmart is benefiting from focusing on select overseas markets, such as India and China, rather than competing everywhere.