The Measurement Wars: Walmart Connect’s Direct Push to Reshape Retail Media

In the high-stakes arena of retail media networks (RMNs), the hierarchy has long been established: Amazon sits on the throne, Walmart operates as the formidable challenger, and a crowded field of secondary players scrambles for the remaining scraps of marketing budgets. However, as the 2024 holiday shopping season approaches, Walmart Connect—the retail giant’s advertising arm—is pivoting from a passive platform to an aggressive, direct-to-brand powerhouse. By bypassing traditional agency intermediaries to offer on-site brand lift studies, Walmart is making a calculated move to capture not just a larger share of the $69.33 billion retail media market, but control over the industry’s most contentious metric: incrementality.

The Strategic Shift: Bypassing the Middleman

For years, the relationship between retailers and brands has been mediated by agencies, which act as the gatekeepers of strategy and measurement. Recent reports from industry insiders indicate that Walmart’s sales team has begun circumventing these agencies, approaching brand clients directly to pitch in-house brand lift studies.

This development is more than a simple sales tactic; it is a signal of Walmart’s ambition to redefine its relationship with advertisers. By approaching brands directly, Walmart is attempting to position itself as a strategic partner capable of providing sophisticated, full-funnel measurement, rather than just a transaction-heavy conversion engine.

While agencies such as Stella Rising and Mile Marker have acknowledged that their clients are being approached, there is a palpable tension regarding the methodology behind these studies. The central concern for marketers remains: Can Walmart prove that an ad campaign actually generated a new sale, or is the retailer simply claiming credit for a purchase that would have occurred regardless?

Chronology of a Data-Driven Offensive

The rise of Walmart Connect has been meteoric. In August 2024, the retailer reported a staggering 38% growth in its global advertising business for the second quarter, cementing its status as one of the fastest-growing RMNs in the ecosystem.

The Path to Measurement Dominance

• Early 2024: Industry discourse shifts toward "incrementality" as CFOs and CMOs begin demanding more rigorous ROI justifications for the ballooning retail media spend.
• Mid-2024: Walmart scales its internal data capabilities, transitioning from offering one-off beta tests for massive enterprise clients to rolling out standardized brand lift studies for a broader range of mid-to-large-sized accounts.
• Q3 2024: The sales team begins a coordinated, direct-to-brand outreach strategy, bypassing agency procurement desks to secure study participants ahead of the Q4 holiday crunch.
• Present Day: Advertisers are finalizing their 2027 budgets, with Walmart’s measurement tools acting as a key "differentiator" in the pitch to keep spend within the Walmart ecosystem.

Anthony Costanzo, chief analytics officer at Mile Marker, notes that these study offers are often tiered based on an advertiser’s total spend via Walmart Connect. While the exact financial thresholds remain proprietary, the shift is undeniable: the "beta test" culture is being replaced by a programmatic approach to proving value.

Supporting Data: The $70 Billion Question

The urgency of this move is rooted in the sheer volume of capital flooding the sector. According to eMarketer, global retail media ad spending is projected to reach $69.33 billion by the end of 2024. As this number swells, the scrutiny from corporate boardrooms has become intense.

"From our experience, Q4 is when advertisers are least willing to fund spend they cannot defend," explains Lacie Edgeman, co-owner and managing director at PrograMetrix. This sentiment captures the "measurement anxiety" that currently plagues the industry. When a brand spends millions during the holiday season, they are no longer satisfied with simple "total sales" metrics. They want to know the incremental value—the lift that would not have existed in the absence of the advertisement.

Walmart’s internal data, which includes granular point-of-sale (POS) information from thousands of physical stores and a massive e-commerce footprint, gives it a unique vantage point. By offering these studies, Walmart is effectively "grading its own homework," a practice that provides brands with immediate insights but raises questions about the neutrality of the data.

Implications for Agencies and Advertisers

The move to bypass agencies has created a complex dynamic. Agencies are, by nature, protective of their client relationships, yet they recognize the value in the data Walmart is providing.

The Double-Edged Sword of In-House Studies

• The "Win-Win" Scenario: When performed correctly, brand lift studies provide advertisers with clear, actionable insights into how their ad creative resonates with different consumer segments. This helps brands optimize their spend in real-time, which is a significant value add.
• The "Walled Garden" Dilemma: The primary drawback remains the lack of standardization. Because each RMN (Walmart, Amazon, Target, etc.) utilizes its own proprietary, "walled-garden" methodology, brands struggle to compare apples to apples. An incrementality score at Walmart is calculated differently than one at Amazon, leaving advertisers with a fragmented view of their total marketing effectiveness.
• The Time Cost: As noted by Edgeman, these studies are not instantaneous. They can take up to nine weeks post-campaign for the reporting to be finalized. For a high-velocity Q4 campaign, this delay can be a significant hurdle for teams looking to make rapid, iterative changes to their media strategy.

"We’re still not able to execute the kinds of incrementality tests we’d like to—the kind we could do in a non-walled garden," says Costanzo. Despite this, he admits that Walmart’s push is a step in the right direction, forcing the rest of the industry to standardize their own reporting to remain competitive.

Official Responses and Market Positioning

To date, Walmart has maintained a relatively guarded stance regarding these specific outreach tactics. The company did not respond to requests for comment regarding its direct-to-brand sales strategy. However, the market’s interpretation of this move is clear: Walmart is signaling its intent to move up the value chain.

By positioning itself as a "full-funnel partner," Walmart is challenging the narrative that retailers are only good for bottom-of-the-funnel conversions. They want to be involved in the brand awareness and consideration phases of the consumer journey. This is a direct assault on the traditional role of digital platforms like Meta or Google, who have historically dominated the upper-funnel media spend.

The Future of the Retail Media Landscape

As we look toward 2027 and beyond, the battle between Amazon and Walmart will likely be fought not on inventory or reach, but on the sophistication of measurement. If Walmart can convince major advertisers that its incrementality data is more accurate, more transparent, or more "actionable" than Amazon’s, it will secure a greater share of the massive Q4 media budgets.

For the advertising industry, this represents a pivotal shift. Agencies will need to evolve, moving away from being mere "media buyers" toward becoming "data integrators" who can synthesize these disparate, retailer-provided lift studies into a cohesive brand strategy.

In the immediate future, brands will continue to participate in these studies, lured by the promise of justifying their spend to skeptical CMOs. However, the industry will eventually reach a breaking point where the "hodge-podge" of different measurement standards becomes unsustainable. Whether this leads to third-party verification, industry-wide standards, or the continued dominance of the largest retail walled gardens remains the most important question in digital advertising.

For now, Walmart Connect has taken the initiative, forcing every other player in the space to respond to a new standard of accountability. The era of "trust us, the ads are working" is over; the era of "prove it to us, or we move our budget elsewhere" has officially arrived.