After a busy 2017, Walmart reported a 44% growth in U.S. e-commerce sales last year. The retail giant acquired four online retailers just last year in an effort to expand its target online shopper demographic. Its retail acquisitions, including its purchase of Jet in 2016, as well as the expansion of Walmart Marketplace helped the company's e-commerce business last year. Here's an analysis of Walmart's e-commerce moves in 2017.