IAB Opens Public Comment on New Guide to Inform Cross-Channel Measurement Decisions

New "Project Eidos" Output Gives Marketers a Decision-First Approach to Interpreting and Applying MMM, Incrementality, and Attribution Results

Public Comment Open Through November 4, 2026

NEW YORK, Oct. 20, 2026 /PRNewswire/ -- Interactive Advertising Bureau (IAB), the leading trade organization for the digital advertising ecosystem, today announced the release of its Cross-Channel Measurement Decision Guide for public comment. Developed as part of Project Eidos, the guide advances IAB's work to help marketers use cross-channel measurement evidence to make better-informed investment and optimization decisions. Public comment is open through November 4, 2026.

The guide gives marketers, agency teams, and measurement partners a decision-first approach to selecting, interpreting, and applying evidence from methods like Marketing Mix Modeling (MMM), incrementality testing, and attribution, including when their findings appear to tell conflicting stories. Rather than starting with whatever metrics happen to be available, it starts with the business decision at hand and works backward to the 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:

• The Decision Guide: Lays out a decision-first sequence, from business outcome to decision, measurement question, measurement approach, evidence, interpretation, and action
• The Decision Navigator: Applies that sequence to common decisions, such as allocating budget across channels or assessing whether an investment is creating incremental value, and helps readers determine which methods fit the question and how to weigh the evidence
• The Measurement Reference Library: Brings together existing metric definitions and supporting context to help readers interpret the evidence used in the Decision Guide and Decision Navigator

"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."

IAB is especially seeking feedback on whether the guide reflects real-world measurement decisions, whether its method-fit and interpretation guidance holds up when results conflict, and whether its scenarios are realistic enough for day-to-day planning. The release directly supports IAB's mission to drive growth, trust, and innovation across the digital advertising ecosystem.

"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."

The public comment period is open from October 20, 2026 through November 4, 2026. To review the Cross-Channel Measurement Decision Guide and submit feedback, click https://www.iab.com/guidelines/getting-digital-out-of-home-on-media-plan 

About IAB

The Interactive Advertising Bureau (IAB) empowers the media and marketing industries to thrive in the digital economy. Its membership comprises more than 700 leading media companies, brands, agencies, and the technology firms responsible for selling, delivering, and optimizing digital ad marketing campaigns. The trade group fields critical research on interactive advertising, while also educating brands, agencies, and the wider business community on the importance of digital marketing. In affiliation with the IAB Tech Lab, IAB develops technical standards and solutions. IAB is committed to professional development and elevating the knowledge, skills, expertise, and collaboration of the workforce across the industry. Through the work of its public policy office in Washington, D.C., the trade association advocates for its members and promotes the value of the interactive advertising industry to legislators and policymakers. Founded in 1996, IAB is headquartered in New York City.

SOURCE Interactive Advertising Bureau (IAB)