’s ecommerce market share dipped to 33.7% in 2018 compared with 35.1% in 2017. It decreased its market share year over year in many retail product categories, although Amazon still dominates or is a key player in most categories.’s share of the ecommerce market dipped slightly in 2018 compared with 2017.

Sales via (not including its app) accounted for 33.7% of all ecommerce sales in 2018, down from 35.1% in 2017, according to Rakuten Intelligence, which tracks email receipts from a panel 3.1 million online shoppers. Rakuten Intelligence’s data does not include sales from Amazon Fresh, Prime Now, apps or marketplaces eBay Inc. and Etsy Inc.

Amazon had the highest ecommerce market penetration of 2018 in the month of December, at 39.0% of the ecommerce market, likely capitalizing on all of the procrastinating holiday shoppers who needed their gifts delivered in time.


November was actually the lowest ecommerce penetration of the year for Amazon, with 28.9% of the market. This is likely because of the high promotional period during the Thanksgiving weekend of Black Friday and Cyber Monday, when most online retailers are offering deep discounts and shoppers are buying at many retailers during this period.

July was the second highest penetration at 36.9%, likely because of Inc.’s Prime Day anniversary sale. Internet Retailer estimates that Amazon sold $4.19 billion worth of goods on Prime Day 2018.

In 2017, Amazon’s share of the market followed a similar pattern.

By category, Amazon has more than half of the online market share in seven of 17 categories.


Amazon is strongest in the books (at 89.7%), toys (70.4%) and baby products (65.0%) categories. This market share, however, is slightly less than in 2017 when books was 89.6% market share, toys 71.5% and baby products 65.9%.

The category that increased its market share the most year over year is flowers and gifts. In 2018, had 25.5% of the ecommerce market in this category, up from 20.7% in 2017.

Amazon did not immediately respond to a request for comment.