Key stat: Amazon reached 235.0 million US unique visitors in June 2026, 67% more than second-place Walmart's 141.0 million and more than the six smallest sites in the top 10 combined, according to June data from Comscore.

Beyond the chart:

• All that traffic decides where shoppers meet a brand for the first time. Some 44% of US adults typically buy a new brand on a marketplace like Amazon or Walmart, more than double the 21% who buy on the brand's own website, according to a March survey from Radial.
• Meanwhile, the fastest growth is happening off this list entirely. EMARKETER expects TikTok Shop to generate $23.41 billion in US sales this year, a bigger ecommerce business than Target, Kroger, Shein, or Best Buy, built on creator feeds rather than the search bar.

Use this chart: Drop this in your retail media budget debate to size the gap between Amazon and everyone else. Show it to leadership asking why marketplace spend concentrates. Use it to benchmark your own traffic share against the platforms your shoppers pass through before they ever reach you.

Related EMARKETER reports:

• US Ecommerce 2026 (EMARKETER subscription required)
• Live Earnings Report: Retail & Ecommerce Tracker Q2 2026 (EMARKETER subscription required)