In 2017 , Amazon 's market share of the U.S. e-commerce retail market was 37 percent , and this is expected to increase significantly by 2021 . As of the date of survey it has been projected that Amazon 's market share will account for 50 percent of the entire e-commerce retail market 's gross merchandise volume ( GMV ) . Amazon 's e-commerce dominance Amazon is the leading online retailer in the United States , offering a wide range of shopping products and services to its customer base . One of the company 's not-so-secret-weapons to increase customer spending is Amazon Prime , a subscription membership that includes free and faster shipping options as well as streaming music and video . As of December 2018 , 62 percent of Amazon 's customers in the United States were Amazon Prime members . This is relevant to Amazon 's success as a company , as Prime members are highly engaged shoppers who spend more than double the amount of non-Prime members on the platform per year . The most popular shopping categories of Amazon Prime members are electronics , apparel and home and kitchen items . Amazon Prime Day In 2015 , Amazon launched its one-day members-only shopping event Prime Day , ostensibly to celebrate the 20th anniversary of Amazon 's founding . However , this Prime-exclusive event has turned into one of the company 's biggest shopping days , rivaling traditional holiday shopping juggernauts Black Friday and Cyber Monday in terms of sales . In 2018 , Amazon Prime Day sales amounted to 4.19 billion U.S. dollars and on Prime Day , shopper conversion was much higher than the average rate of the preceding quarter .
