The Battle for Retail Media Dominance: Walmart’s Direct-to-Brand Strategy Shifts the Measurement Landscape

By Kimeko McCoy | October 22, 2026

In the high-stakes arena of retail media networks (RMNs), the hierarchy is clear: there is Amazon, there is Walmart, and then there is everyone else. As the industry matures and advertisers demand more rigorous proof of performance, Walmart Connect—the retail giant’s advertising arm—is making a calculated play to cement its status as a top-tier partner. In a move that signals a tightening grip on the advertising ecosystem, Walmart has begun bypassing traditional agency intermediaries, approaching brand clients directly with offers for on-site brand lift studies.

This strategic shift, unfolding just ahead of the critical Q4 holiday shopping season, highlights a growing tension in the advertising world: the desperate need for credible incrementality measurement versus the inherent conflicts of interest embedded in "walled-garden" retail platforms.

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The Core Conflict: Measurement and Incrementality

For years, the "holy grail" of retail media has been answering the definitive question that keeps CMOs and CFOs awake at night: “Did this specific campaign drive incremental sales, or did the retailer simply take credit for a purchase that would have happened anyway?”

As digital advertising budgets migrate from traditional search and social toward retail media, the pressure to justify that spend has reached a boiling point. The industry is currently plagued by a lack of standardization, opaque data silos, and a persistent inability to prove that ad spend is actually moving the needle on brand growth.

By offering direct-to-brand lift studies, Walmart is positioning itself not just as a retail destination, but as a sophisticated, full-funnel media partner. The goal is to move beyond the "lower-funnel conversion engine" perception—where ads are only credited for immediate sales—and instead prove the value of awareness and consideration campaigns.

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Chronology: A Shift in Engagement

The outreach campaign, which has been gaining momentum throughout October 2026, marks a departure from standard agency-led negotiations. While retailers have historically offered beta tests to large-spending partners, industry insiders note that the current push is both more aggressive and more widespread.

• Mid-2026: Following a reported 38% increase in its global ad business during the second quarter, Walmart signaled an intent to scale its advertising infrastructure significantly.
• Early Q4 2026: Walmart sales teams began reaching out to brand clients—often without agency representation in the room—to propose bespoke brand lift studies.
• October 2026: Agencies including Stella Rising and PrograMetrix reported that multiple clients had been approached. Sources indicate the frequency of these offers is increasing, trickling down from top-tier accounts to mid-sized brands that meet specific spend thresholds.
• Present Day: As brands finalize their 2027 budgets, these studies have become a pivotal bargaining chip, serving as both a performance evaluation tool and a sales tactic to secure long-term investment.

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The Anatomy of the Offer: Supporting Data

According to Anthony Costanzo, chief analytics officer at Mile Marker, the availability of these studies is tethered to an advertiser’s total spend on Walmart Connect. While specifics remain proprietary, the implication is clear: access to advanced measurement is a premium service reserved for those contributing significantly to Walmart’s bottom line.

Market Context

The urgency for these studies is reflected in the broader economic climate of the retail sector. According to projections from eMarketer, total retail media ad spending is expected to reach $69.33 billion by the end of 2026. As this figure climbs, so does the scrutiny regarding Return on Investment (ROI).

• Growth Trajectory: Walmart’s advertising business is currently one of the fastest-growing in the retail space.
• The Q4 Pressure Cooker: During the final quarter of the year, marketing budgets face the highest level of scrutiny. CFOs are increasingly skeptical of "soft" metrics, demanding empirical data to defend every dollar spent.
• The Cost of Insight: These studies are not without friction. Agencies note that they can be both time-consuming and costly. Reports on campaign performance can take up to nine weeks to process following the conclusion of a campaign, a timeline that many marketers find difficult to reconcile with the fast-paced, real-time nature of modern digital advertising.

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Official Responses and Industry Sentiment

The industry’s reaction to Walmart’s move is a mixture of optimism and caution. Agencies, which traditionally act as the gatekeepers and strategic partners for brands, find themselves in a precarious position.

"Done well, they’re a win for both sides," a spokesperson for Stella Rising stated, acknowledging the potential value of the data. However, the agency community remains wary of the "walled-garden" nature of these reports.

Lacie Edgeman, co-owner and managing director at PrograMetrix, emphasized the strategic pivot Walmart is attempting. "Q4 is when advertisers are least willing to fund spend they cannot defend," Edgeman noted. "Walmart is signaling that it wants to be evaluated as a full-funnel partner… not only as a lower-funnel conversion engine."

Conversely, the critique of these studies often circles back to a fundamental issue: who is verifying the data? "We’re still not able to execute the kinds of incrementality tests we’d like to, that we could do in a non-walled garden," said Costanzo. "Advertisers still lack direct access to independently set up and execute the studies, leaving retailers like Walmart often grading their own homework."

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Implications: The Future of Retail Media

Walmart’s move to offer direct measurement is more than just a sales tactic; it is an "attack angle" on Amazon. By providing the tools to prove incrementality, Walmart is attempting to solve the biggest pain point in the industry. If they succeed in convincing brands that their media spend is truly driving growth, they stand to unlock significantly larger portions of total marketing budgets.

1. The Disintermediation of Agencies

The trend of retailers going directly to brands threatens the traditional agency-retailer-client triad. While agencies remain essential for strategy and creative development, their role in data procurement is being bypassed. Brands must now weigh the benefit of direct access against the loss of an objective, third-party buffer that ensures unbiased reporting.

2. The Standardization Gap

The fragmented nature of RMN measurement remains the industry’s greatest weakness. Walmart’s move may force other major retailers to follow suit, potentially leading to a "race to the top" in measurement capabilities. However, without a universal, independent standard, marketers will continue to struggle with comparing performance across different platforms.

3. The 2027 Budget Outlook

As brands lock in their 2027 strategies, the promise of transparent, incrementality-focused reporting will likely become a primary competitive differentiator. Advertisers are no longer satisfied with simple attribution—they want to understand the "why" behind every sale. Walmart is gambling that by owning the measurement conversation, they will ultimately own the market share.

Conclusion

Walmart’s aggressive push into brand lift measurement is a definitive statement of intent. By offering a clearer window into how advertising dollars function within their ecosystem, they are seeking to move the conversation from simple conversion tracking to sophisticated, long-term brand building.

While agencies remain skeptical of the inherent conflicts involved in a retailer "grading its own homework," the sheer scale of the investment—and the pressure to perform in a high-scrutiny environment—makes these studies an offer that many brands find difficult to refuse. As the Q4 season reaches its zenith and the industry pivots toward 2027, the success of this initiative could fundamentally alter the power dynamic between retailers, agencies, and the brands that fuel the retail media economy.

The question remains: will this move lead to a new era of transparency, or will it simply strengthen the walls around the garden? For now, the brands, the agencies, and the retailers are all waiting for the data to arrive.