Why Retail Media KPIs Don’t Travel—and Why That’s Holding the Industry Back

Retail media results are difficult to compare, and industry alignment, rather than technology, may be the key to more consistent measurement. 

By Mark Baum, Chief Collaboration Officer & Senior Vice President, Industry Relations, FMI 

As retail media investment grows, confidence increasingly depends on one simple test: Do results travel? 

Across FMI's Master Retail Media Series, brand and agency leaders repeatedly described the same challenge. Performance looks strong within individual retail media platforms, yet becomes difficult to compare, reconcile, or scale across partners. 

The issue is not effort or intent. It is structure. 

When KPIs Mean Different Things 

Today, many organizations are trying to evaluate retail media using business-relevant metrics such as iROAS (Incremental Sales ÷ Media Cost) and iROI (Incremental Profit ÷ Media Cost). These metrics resonate because they reflect incremental impact—what changed because of the investment made. 

However, the FMI series participants consistently noted that even these metrics often fail to “travel” across platforms. 

Why? Because: 

• Incrementality is defined and calculated differently. 
• Attribution windows vary by partner. 
• Profit inputs and cost assumptions are inconsistent and/or opaque. 

As one agency leader shared during a live discussion, “We’re normalizing reports before we can even begin optimization. By then, the moment has passed.” 

Without comparability, even the right metrics lose their power to measure outcomes completely and accurately. 

Trust, Transparency, and the Right Questions 

Recent developments across the retail media ecosystem, particularly as platforms expand into pricing, promotion, and measurement, have reinforced a critical lesson for retailers and brands alike: Trust and transparency cannot be assumed; they must be built into strategy, execution, and evaluation. 

Series discussions revealed that brands are increasingly asking: 

• What exactly is included in “incremental” results? 
• What assumptions sit behind the model? 
• What can and cannot be compared across platforms? 

These are not adversarial questions. They are the questions business leaders must ask when investments reach scale. 

Retailers, in turn, are being asked to think beyond performance and consider how transparency, governance, and disclosure affect long-term confidence in their platforms. 

The Role of Industry Translators 

Thought leadership from objective third-party organizations often becomes essential when a retailer needs to understand performance and important consumer issues. 

The trusted advisor role is not to dictate a single methodology, but to: 

• Translate performance into understandable and usable business and finance language. 
• Highlight where inconsistency creates risk. 
• Help the industry ask better questions before locking in answers. 

Technology alone cannot solve a coordination problem. Alignment requires shared understanding. 

Why This Is an FMI Conversation 

Retail media will not scale on bespoke definitions and one-off explanations. Comparability is what allows learning to compound and budgets to move with confidence. 

FMI provides a neutral table where retailers, brands, and measurement partners can align on what must be consistent—while preserving innovation and differentiation. 

That conversation moved forward recently at FMI Midwinter Executive Conference and continues into deeper working sessions at GroceryLab (June), where the focus shifts from identifying the problem to building practical alignment. 

Master Retail Media Series