Amazon Is Closing In on Costco as America’s Second-Largest CPG Retailer
Amazon and Whole Foods combined gained 1.0 percentage point of US consumer packaged goods market share over the 12 months ending June 30, 2026, representing more than $16 billion in additional consumer spending, according to new data from Numerator. That gain puts Amazon and Whole Foods at 8.1% of CPG sales, just 0.1 percentage points behind Costco at 8.2%. Walmart remains the dominant CPG retailer in the US at 20.8%, though its share has been essentially flat over the same period.
The gap between Amazon and Costco in CPG is now so narrow that Amazon is widely expected to cross into second place before the next quarterly measurement. Two years ago, Amazon and Whole Foods together held 6.6% of CPG share. The pace of that gain has accelerated meaningfully in the most recent 12 months.
What's Driving the Shift
Two factors explain most of Amazon's CPG share gain. The first is household adoption. Amazon added 2.6 percentage points in US household penetration year over year, meaning more American homes are now using Amazon for at least some of their everyday product purchases. The second is frequency. Existing Amazon households shopped 11% more often year over year, suggesting the platform is winning routine restock purchases rather than just occasional or research-driven orders.
Both of those signals point to the same underlying behavior change: Amazon is becoming a habitual shopping destination for CPG categories the way Walmart and Costco have been for decades. That is a structurally different competitive position than being a platform people visit occasionally for specific items.
The catalyst for the frequency gain is fairly clear. Amazon expanded same-day delivery for perishables to thousands of cities in summer 2025, adding fresh produce, dairy, and meat to the same-day delivery promise that previously covered non-perishables. Amazon's own internal data shows customers who add fresh groceries shop approximately twice as often as those who do not. Adding a banana or a bag of apples to a same-day order pulls the customer back to the platform on a cadence that packaged goods alone do not create.
Amazon also launched the Amazon Grocery private label brand in October 2025, consolidating the Amazon Fresh and Happy Belly labels into a single brand with over 1,000 items priced mostly under $5. Private-label purchases across Amazon.com, Whole Foods, and Amazon Fresh grew 15% in 2024 compared to the prior year, and the consolidated branding makes those products more discoverable in search.
What This Means for the Retail Media Market
CPG market share is not just a retail metric. It is the foundation of retail media. Amazon's advertising services revenue reached $17.2 billion in Q1 2026 alone, and the value of that business depends entirely on the quality and recency of Amazon's purchase data. Every household that adds CPG purchases to its Amazon activity generates new first-party signals: what brands they buy, how often, at what price points, and in which categories. That data is the product CPG advertisers are paying Amazon Ads to access.
The implication is circular but reinforcing. As Amazon wins more CPG share, its purchase data improves. As its purchase data improves, CPG brands get better targeting and attribution when they advertise on Amazon. As the return on Amazon ad spend improves relative to alternatives, more CPG ad budgets flow to Amazon. That dynamic has been compounding for years and the Q2 data suggests it is still accelerating.
For context on the competitive stakes: a Kroger acquisition of Giant Eagle, if regulators approve it, would push Kroger's food and beverage market share to 8.7%, ahead of both Costco and Amazon. That deal remains pending, but it illustrates how fluid the CPG rankings are right now and how actively every major retailer is trying to defend or expand its share.
What Sellers in CPG Categories Should Watch
If you sell in grocery, household, health and beauty, pet, or baby categories on Amazon, the platform's CPG momentum is directly relevant to your business. More Prime households shopping more frequently means more category-level search volume in these categories, and more data for Amazon's ad systems to work with when targeting your campaigns.
Selling food and grocery products on Amazon carries specific requirements around perishables, shelf life, labeling, and compliance that differ from standard product categories. But for non-perishable CPG sellers already on the platform, the environment is getting more favorable as Amazon captures a larger share of the routine household spending that drives repeat purchase behavior. The customers now shopping Amazon for bananas will see your protein bars, trash bags, and skincare products in the same session.
The flip side is that Amazon's own private label presence in CPG is growing. Amazon Grocery positions over 1,000 items at under $5, directly competing in the everyday essentials price tier where many third-party CPG sellers operate. That tension between a growing CPG customer base and an increasingly assertive Amazon private label strategy is the defining challenge for third-party sellers in these categories right now.
