Retail media is booming.
Spend is climbing, new networks are launching and every platform seems to deliver strong returns. And yet many marketers are asking the same uncomfortable question: How do we know what’s actually driving growth?
These campaigns are working, but the industry lacks a consistent, credible way to prove exactly how much of that performance is truly incremental. As a result, advertisers are often navigating fragmented reporting systems where the numbers look strong on paper, but budget decisions are made on shaky ground.
A classic scale problem
As retail media scaled quickly, each network brought its own rules for defining performance, including different attribution models, different lookback windows and different interpretations of return on ad spend. On the surface, that diversity reflects the unique nature of each platform. In practice, it creates a fragmented system where performance is difficult to evaluate consistently.
Most retail media measurement still relies heavily on attribution models that credit conversions to ad exposure. That approach can be directionally useful, but it leaves out an important part of the story, which is whether those purchases would have occurred regardless of the advertising.
That distinction matters, especially in high-intent environments. A shopper may already be planning to buy, and an ad simply appears along the way. When that happens, attribution credits the ad for an outcome it didn’t create. Over time, this can lead to inflated performance metrics and an incomplete picture of a network’s actual contribution to business outcomes.
For advertisers, that incomplete picture becomes limiting. Budget decisions get harder as more platforms report similar results. Comparing performance across networks becomes an exercise in interpreting different methodologies rather than evaluating real outcomes, even as expectations for accountability continue to rise.
Why advertisers must understand incrementality
Instead of asking which touch points should get credit, marketers are beginning to ask a more fundamental question: What actually moved the needle? That’s where incrementality comes into play.
Incrementality provides a way to measure the true causal impact of advertising. It focuses on the difference between what happened with a campaign and what would have happened without it, helping advertisers understand the genuine effect of commerce media on business outcomes.
That distinction becomes increasingly important as retail media commands a larger share of spend. When every platform reports strong performance, the ability to separate incremental growth from existing demand becomes essential.
Without that clarity, advertisers risk optimizing toward signals that look efficient but don’t reflect real impact. Budgets can shift toward channels that capture demand rather than channels that help create it, while more effective investments may be undervalued.
Incrementality offers a more objective lens. By isolating true lift, it allows brands to assess platform-level performance, optimize spend with greater confidence and more accurately test new products and promotions.
As a result, lift-based measurement is increasingly viewed as the desired approach for understanding a network’s performance and its true value.
Ghost ads are raising the bar for incrementality measurement
Measuring incrementality requires an experiment-based approach that involves comparing outcomes between a group that sees an ad and a group that does not and then measuring the difference in sales to determine lift and incremental return.
Established methods like holdout tests and randomized controlled trials have helped move the industry forward, but they come with trade-offs. Entirely removing users from ad exposure can disrupt the natural dynamics of an auction, introducing bias and making results less reflective of real-world performance.
That’s why ghost ads are gaining traction in retail media. The methodology itself has been used in digital advertising for years to preserve auction dynamics while creating a valid control. Instead of removing users from the system, both control and treatment groups move through the same auction process. One group sees the actual ad, while the other sees a neutral placeholder. This produces a cleaner comparison and a clearer view of causal impact.
What is new is the application of ghost ads to retail media measurement. As advertisers look for more rigorous ways to understand a network’s true contribution to sales, this approach offers a more precise and trustworthy way to measure incrementality.
DoorDash is among the platforms pioneering ghost ads in retail media measurement, and the impacts have proven substantial: We’ve seen a 92% reduction in experimentation dilution and a 35% improvement in ROAS confidence intervals after implementing ghost ads in our lift studies.
How incrementality strengthens the entire retail media ecosystem
The implications of incrementality extend beyond individual campaigns. As advertisers gain access to more reliable measures of impact, they can allocate spend with greater precision, directing investment toward platforms and strategies that drive true incremental growth.
That reallocation has ripple effects across the ecosystem.
Platforms are incentivized to improve the real performance of their ad products, not just how that performance is measured. Publishers and retail media networks that deliver genuine value are more likely to attract sustained investment, while lower-quality or less effective inventory becomes easier to identify.
Over time, this creates a healthier market dynamic, one where performance is defined by actual outcomes and measurement reinforces, rather than obscures, that reality.
Retail media has reached a point where scale is no longer the primary challenge. The next phase is about refinement, bringing greater consistency, accountability and trust to how performance is evaluated.
Incrementality is central to that shift. As experimentation becomes more embedded in the ecosystem, it won’t just improve reporting; it will help shape how platforms evolve, how campaigns are optimized and how value is defined across retail media.
As that standard becomes more widely adopted, it has the potential to move the entire industry toward a more transparent and trustworthy model of growth.
