As the digital advertising landscape evolves, the pressure has increased for marketers to show the ROI of their campaigns. New measurement solutions and strategies are competing with tried-and-true methods to give advertisers clearer paths toward gathering these valuable data insights.

Next year, the quest to improve measurement will open up in a number of different directions.

Increasing investment in measurement methods

Up-and-coming strategies are allowing marketers to bridge measurement gaps in the near term, with marketing mix modeling (MMM) taking a leading role in many advertisers' 2026 plans.

MMM's use of historical data to measure the impact of advertising, promotions, pricing, and external factors on sales and other performance outcomes has proven uniquely powerful.

• Almost half (46.9) of US marketers will invest more in MMM over the next year, per a July 2025 survey from EMARKETER and TransUnion.
• US brand and agency marketers gave MMM as the top answer (27.6%) when asked for the most reliable measurement methodology, per EMARKETER and TransUnion's survey data.

Incrementality is also on marketers' minds, with 36.2% planning to invest more in the methodology over the next year, according to EMARKETER and TransUnion. And over half (52%) of US brand and agency marketers are already using incrementality testing and experiments, per the same data.

Incrementality testing uses causal-based logic to weigh whether results were caused by marketing or not. It can allow for greater precision, but can be resource-intensive, involving setting up control groups, dealing with privacy limits, and more.

• 33% of (CPG) brand marketers and agency professionals say they’re only measuring incrementality at a basic level, according to The State of Retail Media report from Skai and Path to Purchase Institute.
• The top barriers to implementing incrementality measurement are concerns about the accuracy or reliability of results (44%), applying incrementality across ad types/targeting methods/retailers (43%), and limited tools or technologies (41%).

Cookie clarity

Whether or not marketers saw the writing on the wall, Google announced in April that it will continue to offer cookies on its Chrome browser. This reversal to a years-long phase out of cookies gained further clarity when Google wound down its Privacy Sandbox initiative this fall.

Though third-party cookies were once a foundational measurement tool for digital advertisers, Google's back-and-forth on its deprecation has led to an industry that has largely moved beyond cookie dependency.

• Only 5.3% of organizations weren’t looking at cookie alternatives, per an ID5 survey in July.
• Some 36.8% of digital advertising professionals worldwide use cookie alternatives and plan to increase their investments.

On the user side, 38% of US consumers are accepting cookies less often than three years ago, according to a May 2025 Usercentrics and Sapio Research report.

For many marketers, the shrinking importance of cookies has been replaced with the collection of first-party data. Over 4 in 10 (43%) of B2C marketers worldwide say the greatest benefit of collecting and using first-party data to build customer audiences is improved targeting accuracy, according to a July survey from PGM Solutions and Ascend2.

Cookies aren't fully disappearing, either from browsers or from advertisers' toolkits. However, many in the industry have begun prioritizing first-party data, a tactic that will surely continue into the new year.

Agentic measurement

New genAI capabilities are making it easier to think outside the cookie. This month, Google launched Gemini-powered ad assistants, including Analytics Advisor, which helps advertisers identify insights and data anomalies in real time using natural language prompts.

Amazon Ads also rolled out a suite of new AI-powered features this month, including an agentic AI tool geared to managing and measuring full-funnel campaigns.

As measurement strategies incorporate more data sources, advertisers and agencies could lean into these tools in the months to come to grasp the full story behind campaign success and prove ROI.

This was originally featured in the EMARKETER Daily newsletter. For more marketing insights, statistics, and trends, subscribe here.