Digital Commerce 360 analysts rank online retailers around the globe by region. In North America, Digital Commerce 360 ranks and analyzes the Top 2000 ecommerce companies. All companies, whether they operate one URL or 20+ URLs, are ranked by combined annual total web sales. For example, The Gap Inc., which owns Banana Republic and Old Navy, has web sales for all three combined in Digital Commerce 360 rankings under parent company The Gap Inc. For this report, Digital Commerce 360 analysts have removed 143 companies that are headquartered in Canada or Mexico from the data, leaving 1,857 companies headquartered in the United States.

Digital Commerce 360 categorizes each company ranked around the globe into one of 14 merchandise categories.

The Mass Merchant category includes retailers such as Amazon, Walmart, Target, Costco, Macy's and many others that sell products from multiple categories. For this report, their web sales for all products are only included in the Mass Merchant category.