Amazon's 2013 e-commerce sales totaled more than those of the nine other largest U.S. merchants, combined, according to data from Internet Retailer, an e-commerce research firm, Mashable reports.

The online retail giant topped the charts at $67.9 billion — that's $49.6 billion more than the second-largest online retailer, Apple, which clocked in at $18.3 billion. Traditional big-box chains such as Walmart and Staples took third and fourth place, respectively. Netflix, at no. 7, also cracked the top 10 with $4.4 billion. Dell came in at no. 10 with $3.6 billion.

Amazon announced a wearable-technology store late last month and it now lets customers add items to their shopping carts directly from Twitter. The site's sales totaled $19.7 billion in the first quarter of 2014, meeting expectations.