The news: Amazon appears poised to surpass Costco as the second-largest US consumer-packaged goods retailer after gaining 1.0 percentage point of CPG dollar share over the 12 months ended June 30, 2026, per Numerator. It now accounts for 8.1% of CPG sales over that period, just behind Costco at 8.2%.

• Amazon and Whole Foods combined increased share by 150 basis points, from 6.6% in the 12 months ended June 30, 2024, to 8.1%. Amazon’s share gains accelerated in the most recent 12 months.
• Over the same period, Costco’s share increased 80 basis points, from 7.4% to 8.2%.
• Walmart remains the dominant CPG retailer in the US, but its share has been relatively flat, edging down from 20.9% to 20.8% over that period.

Zooming in: Amazon’s push to add perishables to same-day deliveries last year, along with the platform’s vast selection, competitive pricing, and fast delivery speeds, has driven consumers to adjust their shopping habits, enabling it to take more routine purchases from traditional brick-and-mortar retailers. The Numerator data found Amazon continues to broaden household adoption (up 2.6 percentage points YoY) and drive its customers to shop more frequently (11% YoY per household).

That trend aligns with our forecast, which expects Amazon to continue to expand the share of US households that belong to its Prime membership program from 74.1% in 2024 to 76% this year.

Amazon’s ability to continue to add more Prime households—and encourage them to include perishables like apples or bananas in their same-day orders—should significantly increase customer lifetime value. Amazon has found that customers who add fresh groceries shop about twice as often as those who do not. That dynamic aligns with Amazon’s broader finding that the more members engage with the full suite of Prime benefits—streaming, pharmacy, food delivery via Grubhub+, and fast shipping—the more they spend over time. By contrast, nonmembers’ spending tends to remain flat or decline.

Implications for marketers and brands: Amazon’s CPG gains show it is capturing more routine household spending, strengthening the purchase data and recurring demand that power its retail media dominance.