Interactive Advertising Bureau, the leading trade organization for digital advertising ecosystem, has announced release of its Cross-Channel Measurement Decision Guide for public comment. Developed as part of Project Eidos, guide advances IAB's work to help marketers use cross-channel measurement evidence to make better-informed investment and optimization decisions. Public comment open through November 4, 2026.
The guide gives marketers, agency teams, and measurement partners decision-first approach to selecting, interpreting, and applying evidence from methods like Marketing Mix Modeling, incrementality testing, and attribution, including when findings appear to tell conflicting stories. Rather than starting with whatever metrics happen to be available, it starts with business decision at hand and works backward to evidence best suited to inform it.
"Measurement only works if the industry has confidence in the answers it produces, and right now, MMM, incrementality, and attribution can each tell a different story about the same campaign," said David Cohen, CEO, IAB. "This guide doesn't ask marketers to pick a winner among those methods. It gives them a disciplined way to work through the options and make an informed decision they can trust. That's exactly the kind of foundational work Project Eidos was built to do."
The guide has three connected parts: Decision Guide laying out sequence from business outcome to decision, measurement question, approach, evidence, interpretation and action; Decision Navigator applying sequence to common decisions such as allocating budget across channels or assessing incremental value; and Measurement Reference Library bringing together existing metric definitions and supporting context.
"We built this to be used, not just read," said Matt Shapo, Senior Director, Measurement, IAB. "The real test is whether it holds up in an actual planning conversation, like when a channel reports a strong attributed ROAS that an incrementality test doesn't back up. That's exactly the kind of scenario we want the industry weighing in on before we finalize it."
"Marketers rely on measurement to make consequential investment decisions, but they don't always feel confident that their approaches deliver the evidence they need," said David Cohen, CEO, IAB. "60–75% of marketers say advanced measurement falls short across key dimensions such as rigor, timeliness, trust, and efficiency, and this guide helps them connect evidence from different measurement approaches to the decision at hand. It also helps them understand what the findings can support, and identify where additional testing or calibration is needed. That gives brands and their partners a stronger foundation for putting measurement into action."
About IAB
The Interactive Advertising Bureau empowers media and marketing industries to thrive in digital economy. Membership comprises more than 700 leading media companies, brands, agencies, and technology firms. Founded in 1996 headquartered in New York City.
