Retail media ad spend in Europe is set to reach €31bn by 20281 The opportunity is growing fast, but so is the cost of getting it wrong. As brands expand across more retail media networks, comparing performance is becoming harder. When clarity slips, budget decisions slow down and revenue opportunities are missed.
- 24% of brands said they were working with 4–6 Retail Media Networks (RMNs) in 2025, up from 10% a year earlier1.
- 51% of buyers cite fragmentation of RMNs as a persistent barrier1.
For many brands, the challenge is no longer access to retail media networks. It is how to compare retail media performance across retailers and markets with enough consistency to make confident decisions.
The Hidden Cost of Retail Media Fragmentation
Retail media fragmentation rarely shows up as a single obvious problem. And it doesn’t start inside your org. It starts with the ecosystem itself.
No two retailers operate the same way:
- Attribution windows differ across every network
- Performance metrics aren’t standardized, so what counts as a conversion on Amazon doesn’t translate cleanly to Walmart or Instacart
- Each network runs its own algorithm with its own definition of retail readiness
- Strategy doesn’t port over, and data doesn’t stack up neatly without someone reconciling it manually first
That’s the layer of fragmentation that’s easy to underestimate. With over 250 retail media networks in play, the time teams spend figuring out what’s actually comparable adds up fast, and that’s before any real analysis happens.
Inside the org, it compounds:
- Reporting slows down because teams need to reconcile what’s actually comparable
- Performance becomes harder to act on with confidence across different measurement approaches
- Budget decisions get delayed because the data isn’t clean enough to move on
- Opportunities pass while teams are still working out what the numbers mean
Pacvue calls the organizational cost of that the Silo Tax: the measurable drag that builds when teams, budgets, and measurement operate in isolation, showing up as inefficient spend, labor drag, and sales at risk. For a full breakdown of where fragmentation costs brands the most, see Retail Media Fragmentation: The Cost of Data Silos. This piece focuses on the other side: the model leading teams use to compare performance across retailers and act on it.
“The real commercial cost of fragmentation is the latency it injects into your workflow. When you can’t compare performance across retailers on a like-for-like basis, you lose the speed and confidence needed to reallocate budgets effectively.”
Roger Dunn, Principal Consultant, Retail Media & AI Consultancy
This is where the cost of fragmentation becomes impossible to ignore. In a fast-moving retail media market, hesitation is expensive. The teams navigating it best are putting more consistency around how performance is measured, compared and acted on across retailers.
What Leading Teams Do Differently Across Retailers
So how are leading teams navigating this complexity? They’re not trying to standardise everything. Leading teams are not trying to make every retailer look the same. They are creating enough shared structure to judge performance on a like-for-like basis and act faster when it matters.
That means being clearer on what can genuinely be compared, which signals matter most and what should trigger a budget decision. The aim is not perfect uniformity. It is a more reliable way to manage cross-retailer performance as complexity grows.
This is the shift leading teams are making:
“The goal is not to standardise everything. It’s to agree on the metrics and decision rules that allows teams to compare retailers properly and move with confidence.”
Roger Dunn, Principal Consultant, Retail Media & AI Consultancy
The Cross-Retailer Standardisation Model
The Cross-Retailer Standardisation Model is not designed to remove every difference between retailers. It is there to create enough consistency for brands to make sharper investment decisions, reduce avoidable friction and scale with greater control. In practice, it is built around four core elements, and Pacvue helps teams bring that structure into day-to-day execution.
1. Agree Common KPIs
The first step is settling on a common scorecard across retailers. Not more metrics — just a clearer shared view of what the team will use to judge performance, with Pacvue helping teams bring that view together across retailers.
That starts with three decisions:
- Which KPIs are non-negotiable across every retailer?
- How are those KPIs defined, so teams are not comparing different things under the same label?
- Which metrics judge performance, and which are there only for context?
Without that, every retailer conversation starts from a different premise. With it, teams have a more consistent basis for comparison and investment decisions.
2. Set Comparison Rules
The second step is agreeing what “comparable” actually means across retailers. Pacvue acts as a strategic partner in that process, helping teams build a more joined-up view of performance across different retailer environments.
Like-for-like comparison depends on being clear about:
- Where the media ran — onsite, offsite, or in-store
- How performance is measured — for example, whether ads were viewable and whether invalid traffic has been filtered out
- How conversions are defined and how long ads are given credit for driving them
- What reporting limitations or caveats need to be accounted for before results are compared
Without those rules, teams risk comparing numbers that were never truly equivalent. With them, cross-retailer performance becomes easier to interpret on a like-for-like basis.
3. Establish a Review Rhythm
A standardised approach also depends on cadence. Teams need a clear rhythm for reviewing performance, discussing what has changed and deciding when action is needed. When evaluating RMNs, teams prioritise reporting and transparency (82%), performance (76%) and measurement options (75%) — so a consistent way to review and act on those factors matters.
Pacvue gives teams the clarity to agree the factors that create a clear review rhythm:
- How often performance is reviewed
- Which teams or stakeholders are involved
- What decisions should come out of each review
- When a result needs action, not just discussion
4. Define Budget Decision Rules
The final element is deciding what should trigger a budget move. Without a shared view of which signals matter most, teams can see the same performance shift and reach different conclusions. That slows action and makes cross-retailer investment harder to manage.
To move budget with confidence, teams must know:
- Which signals are strong enough to justify moving spend
- When performance needs more time or more context
- Who is responsible for making the call
- How quickly teams are expected to act when conditions change
The goal is not to make every budget decision automatic. Pacvue helps teams put that structure into practice, making budget decisions easier to justify, faster to execute and more consistent across retailers.
How L’Oréal improved cross-retailer visibility and performance
L’Oréal was working across a fragmented retail media landscape, where siloed data and differing retailer capabilities made optimisation and reporting difficult. Using Pacvue’s consolidated cross-retailer dashboard, it gained clearer KPI tracking, stronger budget control and a more joined-up view of performance across marketplaces and across the funnel. This led to:
- +40% ROAS
- +140% sales
- +53% new-to-brand orders
- +63% conversion rate
Read the full Publicis Media for L’Oréal case study to see how the standardisation model played out in practice.
For brands trying to scale retail media across Europe, that kind of structure is becoming harder to do without. As retailer models continue to vary and the market grows more complex, the pressure to make better cross-retailer decisions is only increasing.
For a deeper look at how leading teams are approaching this, download The Hidden Cost of Retail Media Expansion to explore the full cross-retailer standardisation model, including practical frameworks and real-world case studies.
1 IAB Europe, “Retail Media in Europe,” Retail Media Hub, accessed June 22, 2026, https://iabeurope.eu/retail-media-hub/.
