As the No. 1 retailer on the list, Amazon was the main driver of overall retail sales in the U.S. The company's expansive sales figures had a significant effect on general retail as the report found that the company accounted for 20.8 percent of total U.S. retail sales growth.

The DC360 report also points out that Amazon isn't the only online seller experiencing growth. The study found that companies on the backend of the Top 500 saw development as well. Retailers ranked 401-500 this year grew their web revenue by 24.3 percent in 2018 over 2017.

Amazon’s success last year was evident in its record 2018 holiday season, reporting it had its most successful holiday sales figures last winter.