Commerce media is entering a new phase of maturity with global investment expected to exceed $300 billion by 2030.
At the same time, competition for advertising dollars is intensifying. EMARKETER forecasts that annual incremental commerce media ad spending will reach more than $17 billion in 2027 before declining through 2030. As new spending declines, commerce media companies will need to demonstrate results and build confidence in their incrementality measurement approaches by providing greater transparency to earn a larger share of advertisers’ budgets.
That transparency is especially important because methodologies vary across the industry, making incrementality challenging to assess, validate and compare across platforms.
This brief provides an overview of incrementality measurement and steps companies can take to increase transparency and confidence with their partners.
Increasing Transparency is the First Step
As competition for ad spend increases, buyers are looking for stronger evidence of business impact with 29% stating they want higher sales lift and incrementality.
Buyers’ confidence in measurement may ultimately influence the channel’s growth. As AAM CEO Rich Murphy explained in EMARKETER’s "The Next Era of Commerce Media" presentation held during Advertising Week New York, “If buyers continue to question the measurement, the channel might not meet its full potential.”
There isn't one universal approach to measuring incrementality. The methodology used depends on the business goal or marketing question that needs to be answered.
IAB and IAB Europe's Guidelines for Incremental Measurement in Commerce Media identify four major methodologies:
- Experiment-based approaches (e.g., randomized controlled trials, ghost ads, matched markets)
- Model-based counterfactual approaches (e.g., synthetic control, propensity modeling)
- Econometric approaches (e.g., marketing mix modeling, time-series regression)
- Hybrid or proxy approaches (e.g., new-to-brand metrics, baseline vs. exposed analysis)
Organizations should also account for the data inputs required to support these approaches including:
- Deterministic data (e.g., transaction data, logged-in user data)
- Probabilistic data (e.g., modeled or inferred data)
- Supporting calculations and transformations
Regardless of the methodology used, buyers need to know how incrementality was measured to better understand and compare results. The industry may develop greater alignment on measurement as commerce media evolves, but providing transparency on the methodology used is an important first step that can deliver value today.
How Independent Assurance Fosters Trust
While disclosures provide some insight into how outcomes were achieved, independent assurance delivers another level of confidence by independently validating the practices behind the disclosures.
AAM’s Incrementality Certification for Commerce Media verifies measurement practices against industry guidelines including the IAB and IAB Europe’s guidelines. According to a recent report on retail media by the Association of National Advertisers, independent, third-party assurance strengthens confidence in results and promotes greater transparency in the industry.
AAM’s certification focuses on three areas:
- Measurement Methodology and Data Sources
How incrementality models are defined and documented, which data sources are used and the controls and processes supporting measurement. - Incrementality Reporting and Causal Analysis
How incremental impact is calculated and reported, including processes designed to address bias and other influences on results. - Transparency and Disclosure Practices
Whether methodologies, assumptions, limitations and other information needed to understand reported results are clearly documented and communicated.
Murphy says independent assurance can be especially valuable while measurement practices are still evolving.
“When there is no standard or uniform way to calculate incrementality or share metrics, the role of a third party becomes even more important.”
Assurance also provides another benefit by increasing transparency while protecting sensitive underlying data or making competitive assets publicly available. An auditor can evaluate the methodologies, systems and supporting data in a closed environment while protecting proprietary information.
Transparency in Practice: DoorDash
In September 2026, DoorDash became among the first commerce media companies to achieve AAM's Incrementality Certification.
During a presentation at SHOWCASE, the Retail and Commerce Media Upfront by Ascendant Network, Katie Daleo, DoorDash's general manager of CPG ads, said the company’s partners frequently ask about incrementality. She also emphasized that reporting a lift number is only part of the equation.
“As much as the numbers matter, so does the methodology behind them.”
As part of certification, AAM independently reviewed DoorDash ads’ first-party incrementality measurement and reporting for its Sponsored Products and Sponsored Brands, including its methodology, data governance, causal testing framework, metric calculations and customer disclosures.
Daleo explained the value of that review:
“The certification from the Alliance for Audited Media brings greater transparency and consistency to how lift is measured. As methodologies vary across platforms, it gives advertisers more confidence in understanding results and comparing them.”
DoorDash's certification highlights an important point for the broader commerce media market: companies can take meaningful steps by clearly documenting their approach, increasing transparency into how results are determined and opening those practices to independent review.
A Starting Point for Greater Trust
Incrementality measurement will continue to evolve as commerce media matures.
Methodologies across networks may become more aligned over time and buyers may seek comparable approaches across the networks where they invest. But companies don't have to wait for industry standardization to strengthen confidence in their measurement.
By clearly documenting the methodologies used, communicating important assumptions and limitations and independently validating measurement practices against industry guidelines, commerce media companies can give advertisers greater visibility into how outcomes were determined and help them better evaluate campaign performance.
Learn how AAM’s Incrementality Certification can help your organization demonstrate measurement transparency, strengthen advertiser confidence and differentiate its approach in the market.
