Retail Data War Pits Amazon Against Walmart for Ad Cash

Amazon and Walmart retail data is becoming the real prize in U.S. retail: not who rings up the next sale, but who controls the information that tells brands where demand is forming, how shoppers choose, and which ads actually move product.

That is the sharper read on the latest Amazon and Walmart moves, according to PYMNTS. Amazon pushed Prime Day and custom AI chips. Walmart expanded its retail media ambitions through Google and YouTube, while also moving further into premium grocery. The common thread is not merchandise. It is control over the commercial layer around merchandise.

“the future of retail may depend less on who sells products and more on who controls the systems that influence how products are discovered, marketed and purchased.”

That line is the story.

Amazon and Walmart are turning retail data into the new shelf space

For decades, shelf space meant physical placement. Endcaps, circulars, store traffic, and price cuts did the work. Now the valuable shelf is digital, measurable, and tied to identity.

XOOMAR analysis: The Amazon Walmart retail data fight is a contest over consumer intent. Amazon sees intent through search, marketplace behavior, Prime activity, advertising, cloud infrastructure, and subscriptions. Walmart sees it through stores, grocery frequency, pickup behavior, marketplace services, memberships, and retail media.

The winner won’t just sell more goods. It will shape which brands get found, which prices feel reasonable, and which consumer habits become visible to advertisers.

That is why retail data has become more valuable than another price war. Transaction data beats inferred interest. A social click can suggest curiosity. A purchase shows behavior. A repeat purchase shows habit. That is what brands want to buy.

The numbers behind Amazon Ads, Walmart Connect and the retail media land grab

The supplied data shows why advertisers are shifting closer to purchase signals.

In the first half of 2025, consumer spending across retail goods and services rose 3.2% from 2024, according to the PYMNTS Intelligence excerpt. Amazon grew faster. Amazon’s U.S. retail sales surged 9.5% year over year in Q2 2025, with eCommerce up 9.6% and Whole Foods up 7.5%. Walmart grew too, but more slowly: retail sales across stores and online rose 4.6% year over year in Q2, up from 3.2% in the previous quarter.

The share data is more revealing:

The retail media comparison has limits. The supplied material does not provide Walmart Connect growth figures, Prime membership estimates, weekly shopper reach, or retail media market forecasts. So the measurable story is this: Amazon has stronger documented momentum in eCommerce share, while Walmart still owns grocery scale and store-linked frequency.

Another supplied excerpt says Amazon posted $717 billion in sales in 2025, compared with Walmart’s $713 billion. It also says AWS brought in nearly $129 billion, while Amazon generated more than $100 billion from ads and Prime subscriptions combined. Walmart, by contrast, still gets more than 90% of sales from stores and websites.

That difference explains the strategic split. Amazon is already part retailer, part infrastructure provider, part ad platform. Walmart is trying to make its store and grocery base work like a data asset.

For readers following the infrastructure side of Amazon’s strategy, XOOMAR has covered related themes in Amazon AI Chips Muscle In on Nvidia’s Cash Machine and Firing Threat Shadows Amazon Data Center Moratorium.

How Amazon’s marketplace data machine differs from Walmart’s store-first intelligence network

Amazon’s advantage starts with digital intent. Product search, eCommerce purchase history, seller activity, and ad attribution sit close together. That makes the company powerful for brands that want to connect ad spend to sales inside one commerce loop.

Walmart’s advantage is different. It has the source’s clearest lead in grocery, where Walmart holds 21% share versus Amazon’s 2.7%. Grocery is repetitive, habitual, and household-driven. That gives Walmart a window into essentials spending that Amazon has not matched.

The two models are converging.

Amazon is pushing infrastructure and AI chips, not just retail promotions. PYMNTS frames this as part of Amazon’s effort to control more of the infrastructure powering its technology businesses. Walmart is expanding retail media through a partnership with Google and YouTube, giving advertisers greater access to Walmart shopper data and closed-loop measurement.

XOOMAR analysis: Amazon starts with the digital transaction and tries to add more physical touchpoints. Walmart starts with physical frequency and tries to add more digital measurement. Both want the same prize: a larger role between consumers, brands, advertisers, and commerce infrastructure.

From price wars to identity graphs: how the Amazon-Walmart rivalry changed

The old rivalry was easier to score. Walmart dominated physical retail. Amazon dominated eCommerce. The fight centered on delivery speed, pricing power, market share, and store traffic.

Now those metrics are inputs, not the whole game.

PYMNTS says Amazon found higher-value opportunities in cloud computing, advertising, and subscriptions. Walmart sees them in advertising, marketplace services, memberships, and data monetization. Retail still matters, but it increasingly acts as the acquisition channel for higher-margin activity.

This is the modern version of old retail power. Slotting fees and endcap placement gave retailers influence over what shoppers noticed. Retail media and first-party data do the same thing with tighter measurement and more granular targeting.

The Amazon Walmart retail data battle is therefore not a side business. It is the next version of merchandising power.

Brands, shoppers, regulators and smaller retailers face different risks

For brands and advertisers, the appeal is obvious.

• Attribution: Retail media can connect ads more directly to purchases.
• Targeting: Retailers observe actual buying, not just browsing.
• Measurement: Walmart’s Google and YouTube partnership is specifically framed around access to shopper data and closed-loop measurement.
• Budget pressure: If retail captures a smaller share of consumer spending, brands need sharper proof that ad dollars drive sales.

For shoppers, the picture is mixed. More relevant promotions may be useful. Less clear is how purchase histories and shopping patterns are packaged, shared, or used across advertising systems. The supplied source does not report a specific privacy dispute or regulatory action here, so that concern should be treated as a structural risk, not a current case.

For smaller retailers, the danger is strategic. If Amazon and Walmart control the richest commerce data, others risk becoming inventory suppliers with thinner margins and weaker advertiser demand.

Retailers that can’t monetize first-party data risk becoming inventory suppliers

The practical lesson for grocers, specialty retailers, department stores, ad tech vendors, and consumer brands is blunt: scale without usable data is losing value.

Retailers that want to compete for ad dollars need clean identity systems, repeat customer relationships, measurable media products, and better links between online and store purchases. Otherwise, ad budgets will keep moving toward platforms that can show what happened after the impression.

A defensive plan does not require becoming Amazon or Walmart. It does require discipline.

• Identity: Build customer records that work across store, app, pickup, and delivery.
• Loyalty: Give shoppers a reason to identify themselves repeatedly.
• Measurement: Prove sales lift without overstating precision.
• Privacy controls: Make data use clear enough that shoppers don’t feel trapped.
• Partnerships: Use media and commerce partners where in-house scale is too small.

Retail media’s next test is trust, not just targeting

The next phase will reward the retailer that proves sales impact without making brands feel dependent or shoppers feel watched.

Amazon has the stronger documented eCommerce momentum, a growing share of wallet, and large non-retail profit engines around AWS, ads, and Prime subscriptions. Walmart has grocery frequency, store reach, and a fresh push to connect shopper data with Google and YouTube advertising.

The evidence that would confirm the thesis is clear: more advertiser products tied to purchase measurement, more data partnerships, and more retail revenue coming from advertising, memberships, cloud, marketplace services, or subscriptions rather than merchandise margin alone.

The evidence that would weaken it would be just as clear: brands resisting retail media measurement, shoppers pushing back against data use, or retailers failing to turn transaction scale into high-margin revenue. Until then, the Amazon Walmart retail data race is the new center of the rivalry.

The Bottom Line

• Retail data is becoming more valuable than simply winning the next sale.
• Brands increasingly want transaction and repeat-purchase data because it shows real shopper behavior.
• The Amazon-Walmart rivalry could shape which products shoppers discover, what ads they see, and how prices are positioned.