In this week’s Guest Member Blog post, we hear from Andreea Mandeal, Chief Marketing Officer at iubenda, who explores why European marketers are placing transparency ahead of accuracy when it comes to measurement. The article examines how trust, consent quality, and privacy-first approaches are becoming critical drivers of performance, data reliability, and long-term audience relationships across the digital advertising ecosystem.
Buried in Nielsen's 2025 “Europe in focus” report is a result that should reframe how the ad ecosystem thinks about the next few years. Asked what they prioritise most in measurement technology, European marketers were the only region in the world to rank transparency ahead of accuracy.
Sit with how strange that is. Given a choice between the most precise measurement and the most transparent, the region that invented modern privacy regulation chose transparency. That is not a soft preference. It is a signal about where value is moving in a market under real pressure, and it has direct consequences for publishers, platforms, and everyone building on shared consent standards.
The pressure is easy to document. In the same Nielsen report, 60% of European marketers forecast a cut in ad spend, against a 54% global average. When budgets contract, acquisition gets rationed and retention becomes the priority: 43% of European marketers now rank retaining existing customers as their first or second concern.
Retention changes what data has to do. Acquisition can run on broad reach and probabilistic targeting. Retention runs on a relationship, and a relationship runs on trust. That is where the numbers turn uncomfortable. Deloitte's 2023 research found that only 34% of consumers believe companies are honest about how they use their data. Two-thirds of the audience a retention strategy depends on start from doubt.
You cannot measure your way out of that with better attribution. If the data underneath the measurement was collected in a way people resent, precision only tells you more exactly how a distrusted message performed. European marketers appear to understand this intuitively, and it is why transparency, not accuracy, sits at the top of their list. Accurate measurement of an eroding relationship is still measurement of an eroding relationship.
For anyone working in programmatic, the interesting part is that this is not only a brand-side problem. Consent quality is now an ecosystem input. A vague or manipulated consent decision does not just risk a fine. It produces a weaker, less reliable signal that travels downstream into every bid, segment, and measurement model built on top of it.
This is exactly the problem shared standards were built to solve. The Transparency and Consent Framework (TCF) and the Global Privacy Platform (GPP) exist so that a person's choice can move cleanly across the supply chain and be honoured consistently. The infrastructure for trustworthy, portable consent is already in place. What varies wildly is the quality of the choice feeding into it at the top.
That is the gap worth closing. When the consent signal is genuine, the whole chain inherits a more durable asset: data a person actually agreed to share, that keeps its value as regulation and browser policy tighten. When the signal is coerced, everyone downstream is optimising against noise, and the audience is quietly learning to disengage.
Working with marketing and data teams at iubenda, we notice which teams end up with data they can actually rely on, and it is rarely the ones with the most sophisticated activation tools. It is the ones that got the consent decision right at the point of collection, before anything downstream came to depend on it. When that groundwork is rushed, no amount of clever measurement further along the chain makes up for it.
The practices that weaken consent are rarely dramatic. A rejection option styled to be missed, a preference centre that takes real effort to reach, wording vague enough that no one can say what they actually agreed to. Choices collected this way still register as a yes, but it is a brittle one: the person did not decide so much as give up. A reluctant yes behaves nothing like a genuine one once it flows into the systems that rely on it, and that is how you end up with consent records that look like agreement and perform like resentment.
The reassuring finding is that fixing this does not require sacrificing performance. Research from Google and Ipsos shows that giving people more control does not reduce engagement. It increases brand trust and preference. Control and results are not in tension. The trade-off marketers fear is largely imaginary.
Put the three findings together and a strategy falls out of them. Budgets are pushing European marketers towards retention. Retention depends on trust. Trust depends on how consent is collected and honoured. And Europe, shaped by years of General Data Protection Regulation (GDPR) awareness, already has both an audience that expects transparency and the standards infrastructure to deliver it at scale.
That combination is rare. Most markets are still treating consent as a cost centre and measurement as the thing that matters. European marketers, by ranking transparency first, have quietly identified the more durable edge. The teams that act on it will not just clear the compliance bar. They will hold the one advantage a better-funded competitor cannot copy quickly: an audience that believes them, and a consent signal strong enough for the rest of the ecosystem to build on.
Photo by Campaign Creators on Unsplash
