As the programmatic landscape continues to evolve, publishers are balancing innovation with operational resilience. In this month’s recap, we examine Prebid’s move into agent-based selling through the Sales Agent and what it signals for open infrastructure, unpack Microsoft’s decision to shut down its Prebid video caching service and its practical implications, and share concrete test results from bidder-specific pricing in AdX.
The common thread across these developments is clear: automation is accelerating, infrastructure decisions are becoming more critical, and measurable optimisation requires both control and visibility. For publishers, the focus is no longer just on adopting new features, but on testing, safeguarding revenue streams, and building a setup that remains flexible as the ecosystem continues to shift.
Prebid Launches Sales Agent. What Does It Mean for Publishers?
At the end of January, Prebid announced that it is taking stewardship of the Prebid Sales Agent in collaboration with AgenticAdvertising.org. The sell-side agent solution, originally developed under the Ad Context Protocol (AdCP) framework, is now part of Prebid’s open-source ecosystem alongside Prebid.js and Prebid Server. The aim is to enable agent-driven automation in direct and programmatic sales workflows within an open infrastructure.
For publishers, this is not yet a plug-and-play feature but a strategic signal. Agentic advertising has so far been discussed largely at a conceptual level or developed within closed environments. By bringing the Sales Agent into open infrastructure, Prebid lowers the barrier to experimentation and helps ensure that sell-side automation does not become another proprietary layer in the stack.
Relevant Digital’s CPO, Ronny Linder, who has been part of the Prebid Task Force since its inception, sees this development as both promising and demanding in practice:
“I think it is really good that Prebid is an active driver of the development of the Sales Agent, as it has ambitious goals, but in my view, it is still some distance away from being a practical, scalable alternative. At the core, there are many basic problems that need to be solved, both technical and fundamental, and right now we are trying to define and solve them one by one in the Prebid Task Force.
Prebid has always been about building and making things work at scale, so I think it sits very well in the Prebid community. Even though it would technically work, it does not necessarily bring enough value to the market to be adopted at scale. In the end, it is about delivering enough value to the market (both publishers and buyers) to justify the extra effort of handling another sales pipeline, I think.
Arguments have been made about removing middlemen and technical fees, but at the same time, no one is going to build and maintain advanced Sellers and Buyers agent systems for free, so it seems more like some companies are trying to maybe disrupt the traditional market players, like SSPs and DSPs, by introducing alternatives. But are those going to be free?
And if I am being slightly cynical, this would basically introduce “cuts” in the direct sales pipeline, so in the end, you could ask whether this is more about redistributing fees between technical providers and gaining access to new sales channels than actually cutting tech fees. On the other hand, agents may also bring in new advertisers and incremental demand, in which case a potential commission could be justified by the additional value they create.
I encourage publishers to be curious about this, but also do the math, and approach this with a critical mindset, and try to analyse where the “cuts” will go in the future and whether there is real value in this for them.“
At this stage, this is primarily about direction, not a finished solution. An open development model gives publishers the opportunity to follow and test the evolution without immediate commitment, but ultimately, the decisive factor will be whether measurable value is created in the market. The future of agent-driven sales will not be determined by technical feasibility alone, but by whether it genuinely shifts the commercial dynamics in publishers' favour.
- Ronny Linder - CPO, Partner and Member of Several IAB Tech Lab Task Forces & Suvi Leino, Head of Marketing
Microsoft Ends Prebid Video File Caching: What You Need to Know
Microsoft will discontinue its Prebid video caching service on April 30 in connection with the shutdown of the Xandr DSP. Historically, this service acted as a temporary storage locker for ad creatives, ensuring they were in the right format for your video player to read.
What is happening?
Microsoft is transitioning away from hosting these files. This means any Prebid auction still relying on the Xandr cache URL (e.g., prebid.adnxs.com/pbc) will fail to deliver ads once the service is shut down. Without a cache, the video player cannot retrieve the ad, leading to delivery errors and lost revenue.
What this means for Relevant Yield (RY) customers:
If you use HB Manager to manage your video header bidding, we have already prepared for this transition to ensure your revenue is not interrupted.
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A Ready-to-Use Solution: The Relevant Yield team has already taken proactive action. We provide a dedicated caching service hosted by Relevant Digital, replacing the need for Microsoft’s infrastructure.
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Seamless Transition: Because we host the service, we ensure full compatibility and reliability for your video setups without relying on third-party deprecation timelines.
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HB Manager Support: Within the Relevant Yield interface, your configurations can be seamlessly transitioned to the Relevant Digital-hosted cache, keeping your video delivery stable and your reporting accurate.
- Barbara Jerko - Solutions Engineer
Test: What Was Achieved with Bidder-Level Pricing in AdX?
Google has recently enabled bidder-level pricing for Ad Exchange demand within Google Ad Manager. In practice, this means you can set pricing individually for each bidder based on how they typically behave in the auction.
If you know that a specific demand partner tends to submit higher bids, you can test a higher price level and evaluate whether demand remains stable while revenue increases. Conversely, for bidders who typically bid lower, you can experiment with a lower price. The goal is not simply to raise prices, but to find the right balance that improves overall revenue without significantly harming fill rate.
Relevant Digital has run two separate tests from January to February:
In the first test the setup was fairly typical, with the header bidding setup built on top of Google Ad Manager:
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GAM+AdX running with Header bidding and competing with the highest bidder from Prebid
The second test scenario was done with the publisher non-Google adserver + Header bidding on an initial call and if this did not provide an ad - a secondary ad call was done with GAM + AdX - This test to some extent also simulates a situation where GAM+AdX are running on a site without header bidding involved:
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GAM+AdX secondary call with no Prebid / Header bidding
In both setups, revenue growth was observed. In some environments, the increase was around 0.5 per cent, while in others it was close to 10 per cent. The results show that bidder-level pricing can provide clear incremental potential. However, the impact depends heavily on your inventory, demand structure, and competitive landscape.
From a publisher's perspective, controlled testing and holistic measurement are essential. An increase in eCPM alone is not enough if auction dynamics change or demand shifts from one channel to another. With the Relevant Yield platform, these tests can be executed systematically and monitored in real time at the bidder, SSP, and auction levels. This allows you to quickly see whether the change genuinely drives incremental revenue or simply redistributes demand. Real-time visibility enables fast reaction and continuous optimisation without guesswork.
New features create opportunities, but value is only realised when they are tested, measured, and optimised as part of a broader yield strategy.
- Simo Kulmala - Head of Programmatic