Supply-Side Targeting Spend Doubles as Buyers Move Beyond Inventory Curation

New research from OpenX shows how audience data, quality signals, measurement, and algorithmic optimization are expanding the role of supply-side intelligence in media buying.

NEW YORK--(BUSINESS WIRE)--OpenX, The Intelligent SSP^™, today released its Supply-Side Intelligence Trend Report, revealing that supply-side targeting (SST) spend doubled year-over-year in 2025. The data strongly suggests buyers are moving beyond inventory packaging to apply more sophisticated intelligence closer to the source of supply.

Building on its legacy in identity solutions, OpenX is using marketplace evidence to show how SSPs create value beyond inventory packaging. Drawing on four years of U.S. transaction data, regional comparisons with EMEA, and interviews with eight senior buy-side executives, the report points to an expanding role for SSPs: not simply providing access to inventory, but informing which impressions buyers pursue and how they evaluate those opportunities.

“It just makes sense that you would get better data fidelity by working closer to the publisher. So it makes sense to apply data on the SSP whenever possible,” said Chris Milano, Global VP of Supply, Stagwell Media.

For brands and agencies, that shift makes the intelligence behind a deal increasingly important. Inventory selection alone doesn’t explain which audiences a deal reaches, how it evaluates the advertising environment, or whether predictive models and real-world outcomes inform buying decisions. The report proves that buyers benefit from assessing those capabilities directly, rather than treating all supply-side activation as “curation.”

“We need to move beyond simply using the word ‘curation’ because it has become too vague and means too many different things to different people,” said Wade Wilkinson, Director, Platform & Technology Partnerships, Sojern. “The important distinction is between simply packaging inventory and using intelligence within that packaging to make better decisions.”

The report defines supply-side intelligence as tools within an SSP that help buyers choose better inventory, improve campaign performance, and streamline workflows. It defines curation as focusing on inventory selection, such as choosing sites and setting viewability requirements. Supply-side targeting goes further, using audience data, quality signals, and predictive models to guide buying decisions.

The report highlights four findings that indicate how buyers are putting supply-side intelligence to work:

• SST spend is growing ~2x annually with the share of spend using SST at 11% in Q4 2023, 19% a year later, and 37% a year after that.
• 17% of deals in 2025 included measurement to build and validate audiences using real-world outcomes, signaling a shift beyond digital proxy metrics toward connecting ad exposure with physical behaviors and offline actions.
• 500% growth in CTV spend using SST from H1 2022 to H1 2025, as buyers make greater use of content signals such as genre and rating to identify relevant inventory.
• ~11% average quarterly growth in SST in both U.S. and EMEA since Q1 2025, indicating sustained momentum and growth across both markets.

"The doubling of spend in 2025 shows that buyers increasingly understand the need to work more closely with SSPs,” said Tyler Romasco, EVP, Commercial at OpenX. ”Buyers see real value in the data that lives closest to the impression and in the decisioning that can happen on the supply side. When intelligence gets applied earlier in the process, buyers get better results, and publishers get more value from their inventory."

The full OpenX Supply-Side Intelligence Trend Report is available here.

About OpenX

OpenX is The Intelligent SSP^™ (supply-side platform), simplifying advertising for marketers, advertisers, and publishers worldwide. As one of the largest SSPs globally, OpenX combines the industry’s only fully cloud-based infrastructure with leading AI capabilities to make digital advertising easier and more effective across every format, including CTV. Built to responsibly deliver quality, performance, and adaptability, OpenX makes digital advertising safer, smarter, and built for what’s next. Learn more at www.openx.com.