Amazon's tightening grip on U.S. retail is growing even tighter during holiday shopping season as the internet shopping giant's fourth-quarter margins have improved markedly in the past five years. Their closest retail peer, Walmart, has seen margins drop over that period as the discount retailer vies for shoppers.
Amazon's sales revenue in the fourth quarter of 2017 was $60.5 billion, up from $43.7 billion in the fourth quarter of 2016, or 38% higher. While Walmart had more than double the sales at $131 billion, it barely represented a 1% change from the fourth quarter of 2016.
