Supply-side targeting is gaining momentum as advertisers look for richer audience signals, while privacy restrictions continue to challenge addressability. Meanwhile, publishers are reconsidering how they measure audience value and prepare for AI-driven media trading. These developments point to a growing need for stronger data intelligence and greater control over monetization.
The relationship between publishers, advertisers, and technology platforms is evolving as more advertising decisions move closer to the source of inventory.
New research from OpenX shows rapid growth in supply-side targeting, with buyers increasingly relying on audience data and quality signals to guide their investments. At the Prebid Summit, addressability returned to the agenda as industry leaders discussed the growing influence of platform restrictions. Meanwhile, publishers gathering in London raised questions about measuring engagement, managing AI crawler access, and preparing for agentic media trading.
Together, these developments highlight a broader shift: the ability to understand, demonstrate, and activate audience value is becoming increasingly important to publisher monetization.
Supply-side intelligence expands the value of publisher data
Supply-side platforms have traditionally helped advertisers access inventory through exchanges and curated marketplaces. However, buyers are increasingly looking for more sophisticated intelligence to determine which impressions are worth purchasing.
According to OpenX’s Supply-Side Intelligence Trend Report, spending using supply-side targeting (SST) doubled year-over-year in 2025. Within OpenX’s marketplace, the share of deal spend using SST increased from 11% in Q4 2023 to 19% in Q4 2024 and 37% in Q4 2025.
The findings reflect OpenX’s own transaction data, but they provide a useful indication of how buying strategies are evolving.
Traditional inventory curation focuses on selecting publishers, placements, and inventory characteristics, such as viewability or content categories. Supply-side targeting introduces additional intelligence, using audience data, quality signals, and predictive models to inform buying decisions closer to the impression.
This changes how publishers can demonstrate the value of their inventory.
Two impressions from the same website may offer different opportunities depending on audience characteristics, contextual relevance, or engagement. When these signals are available to buyers, inventory can potentially be evaluated with greater precision.
OpenX also reports that 17% of its deals in 2025 included measurement capabilities connecting advertising activity with real-world outcomes. This suggests growing buyer interest in understanding campaign effectiveness beyond conventional delivery metrics.
For publishers, the opportunity lies in making their audience intelligence more useful to demand partners. First-party data, contextual information, and engagement signals can help advertisers identify relevant opportunities, provided that the data is accurate, privacy-compliant, and accessible through the appropriate integrations.
However, greater use of supply-side intelligence does not automatically translate into higher publisher revenue. The impact depends on how these capabilities influence advertiser demand, auction competition, and the value of individual impressions.
Publishers should therefore evaluate supply-side targeting through measurable results, comparing demand participation, CPMs, and revenue performance across different partners and activation methods.
Sources: Yahoo Finance, OpenX
Addressability concerns bring supply-side signals back into focus
While buyers are investing in richer audience intelligence, the industry’s ability to identify and reach users remains uncertain.
At the October 13 Prebid Summit in New York, addressability returned as a central concern following Apple’s latest restrictions affecting advertising technologies.
The discussions highlighted an ongoing challenge for the open web: browsers and operating systems can influence which identifiers and targeting technologies remain available, often with consequences for advertisers and publishers.
This creates a particular disadvantage compared with walled gardens.
Large platforms such as Meta operate within ecosystems where audience information, advertising activity, and campaign measurement are more closely connected. Open-web publishers operate through multiple technology partners, making addressability and measurement more dependent on external integrations.
At the summit, Permutive CEO Joe Root pointed to Meta’s use of supply-side signals as an example of how advertising intelligence can be built around data available within an ecosystem. He suggested that publishers are increasingly looking to move more audience intelligence and decision-making onto the supply side.
For publishers, this direction could strengthen the role of first-party data and contextual signals in programmatic advertising. These capabilities may help buyers identify relevant audiences even when traditional identifiers become less reliable.
However, implementation requires careful consideration of privacy requirements, consent, and the technologies used to share or activate data.
Publishers also need visibility into how addressability restrictions affect their monetization. A change in browser behavior can influence match rates, demand participation, and advertising yield, even when traffic volumes remain stable.
Monitoring performance by browser, device, demand partner, and audience segment can help teams identify these effects and distinguish technical limitations from changes in advertiser demand.
As platform restrictions continue to evolve, maintaining flexibility across targeting methods and demand relationships becomes increasingly important.
Source: Digiday
Publishers reconsider audience value as AI changes media economics
The evolution of audience intelligence is also influencing how publishers measure the value of their content and audiences.
During Digiday’s London Media Strategies Town Hall, publishing executives discussed the limitations of traditional traffic metrics as AI changes how content is discovered and consumed.
Page views remain useful for understanding traffic, but they provide limited information about audience relationships or the commercial value generated by engagement.
Executives discussed alternative measurements that combine unique visitors, subscriber activity, dwell time, and conversions. The challenge is developing metrics that editorial and commercial teams can interpret consistently and use to make decisions.
AI introduces another complication.
Publishers increasingly need to distinguish human audiences from automated traffic generated by crawlers, bots, and AI agents. These interactions have different implications for content distribution, advertising opportunities, and revenue.
Controlling AI crawler access is becoming a strategic decision. Restricting access may help publishers protect content and strengthen their position in licensing negotiations, but it could also limit their visibility within AI-powered discovery systems.
The long-term commercial effects remain uncertain, particularly while licensing models and AI referral behavior continue to develop.
Meanwhile, agentic media trading is attracting interest as another possible change to the relationship between publishers and advertisers.
At the Town Hall, one publisher described developing a selling agent intended to interact with buying partners. The technology was still at an early stage, with further testing required.
The potential is significant. Automated trading systems could eventually allow publishers to communicate inventory characteristics and commercial preferences more directly to buyers, potentially reducing some of the complexity associated with programmatic intermediaries.
However, successful adoption will depend on technical interoperability, partner participation, and evidence that these systems improve commercial outcomes.
For publishers, these discussions reinforce the importance of connecting audience, content, and monetization data. Understanding which audiences engage, how content creates value, and where revenue originates will help teams evaluate emerging opportunities without relying solely on traffic volume.
Source: Digiday
What these signals mean for publishers
The developments reported by OpenX and Digiday suggest that publisher-controlled intelligence is becoming more relevant to how advertising value is assessed and exchanged.
Supply-side targeting is increasing the importance of audience and quality signals in buying decisions. Addressability restrictions continue to expose the open web’s dependence on external platforms, while AI is encouraging publishers to reconsider how they measure engagement and commercialize their content.
Publishers should focus on improving the quality and usability of their first-party and contextual data, while maintaining visibility into how those signals influence advertising performance.
This includes evaluating supply-side partnerships against measurable revenue outcomes, monitoring changes in addressability, and developing clearer connections between audience engagement and monetization.
AI-driven discovery and emerging trading technologies introduce additional opportunities, but their value will need to be tested against practical business results.
As advertising decisions become more data-driven, publishers with a clearer understanding of their audiences and stronger control over how that intelligence is activated will be better positioned to respond to changes in demand.
The priority is to turn the information publishers already generate into more informed monetization decisions, while protecting the audience relationships that make their inventory valuable.
