AdMonsters’ Sell Side Summit laid bare the tensions—and opportunities—that will define 2025. Can buyers and sellers find common ground, or is this industry stuck in a perpetual playoff series?
From the keynotes to the workshops and roundtables, AdMonsters Sell Side Summit was a front-row seat to the evolving power dynamics in digital advertising. And right now, it’s feeling a lot like a full-court press, with buyers doubling down on efficiency and control as publishers scramble to find their footing.
The old playbook? Dead. In its place: direct deals, clean supply paths, and ruthless scrutiny over data-sharing practices. Meanwhile, sellers are fighting to maintain value in a world where automation, AI, and curation are shifting the balance of power.
Publishers are responding to SPO inefficiencies, challenging the economics of curation, and redefining data monetization. The real question isn’t whether the sell side is adjusting—it’s how fast they can make those adjustments stick.
Buyers Are Running the Fast Break—Can Sellers Keep Up?
Buyers no longer want a seller’s sales deck. They want data. And they want it served up in the cleanest, most efficient way possible.
“We want the most efficient path with the greatest transparency to the cleanest inventory,” said Stephani Estes, Chief Media Officer at Goodway Group, during her keynote. And, at Goodway Group, they’re not just talking about transparency—they’re acting on it.
- SSP consolidation is real. Buyers are slashing partnerships, favoring direct-to-DSP models like OpenPath and Backstage. Some are even cutting SSPs out entirely.
- RFPs are dead. Instead of endless pitches, buyers are turning to clean rooms, audience propensity modeling, and real-time data sharing to determine where to spend.
- Measurement matters. Performance is not about clicks—it’s about business impact. Buyers need proof that audiences convert, not just that they exist.
AdMonsters Buyer Barometer report shows just how much buyers are reshaping their approach:
- 56% of brands are actively involved in inventory decisions, signaling that buyers aren’t just relying on agencies—they want more control over where their dollars go.
- 34% of buyers anticipate switching partners, meaning sellers who can’t meet these expectations risk getting cut.
- 59% of buyers now prioritize principles over performance, a clear sign that transparency, sustainability, and brand alignment influence deals as much as efficiency.
“Programmatic is not a Consumer Intelligence Center,” said Albert Thompson, Managing Director, Digital Innovation at Walton Isaacson.
That single statement highlights a hard truth—buyers still need deeper insights, audience context, and strategic partnerships beyond just bidding efficiencies. It’s not enough to be in the right place at the right price. Sellers who can’t demonstrate audience value beyond transactional metrics risk being viewed as just another commodity.
To their credit, sellers recognize that simply throwing inventory into a curated PMP isn’t cutting it. Publishers debated how to monetize data more effectively—without handing over the keys to their most valuable asset.
Some argued that transparency could work in their favor if they controlled the narrative. Others pushed for a first-party data consortium, a seller-led solution to keep publishers from being squeezed out of their own deals.
Curation: Whose Playbook Are We Following?
Depending on who you ask, curation is either the future of publisher revenue or another way for SSPs and intermediaries to siphon margins away from publishers.
“We’re under attack by the least likely of players—the SSPs,” said Ryan Maynard, VP of Programmatic Sales at Raptive.
While buyers are leaning into curated PMPs, publishers realize that these deals often come with opaque pricing and hidden fees. The economics aren’t pretty:
- SSPs charge 4-5% for direct publisher-sourced PMPs. But for curated PMPs, that number can jump as high as 20%.
- Publishers have little control over floor pricing. SSPs often dictate pricing structures without publisher input, leading to a race to the bottom.
- Agencies are pushing buyers into curated deals. Some holding companies now mandate that buyers use SSP-curated paths, sidelining direct publisher relationships.
But curation isn’t inherently bad. “Curation is good as long as you’re in control,” said Jana Meron, Strategic Advisor at Lioness Strategies.
And, that’s the sell side’s biggest challenge. If publishers don’t take ownership of curation strategies, they risk being stuck in a zone defense while the buyers set the tempo.
This was a recurring theme throughout the Summit—how do publishers regain control? One idea floated was a publisher-led curation marketplace, one that bypasses SSPs and intermediaries altogether. The concept isn’t new, but with mounting frustration over current curation economics, it’s an idea that’s gaining real traction.
Transparency: A Full-Court Press on Sellers
Transparency is one of the industry’s favorite buzzwords, but it’s a double-edged sword for publishers. Buyers demand full visibility into where their ads run, yet those same demands often come with arbitrary restrictions.
Take the brand safety debate. “We should not be using the word ‘safety’ when it comes to ads. No ad is going to kill you,” exclaimed Meron. Yet publishers continue to get blocked over suitability concerns—sometimes for ridiculous reasons. (Yes, crossword puzzles have been flagged for murder clues.)
For sellers, there’s a big difference between transparency and surrender. The sell side isn’t opposed to giving buyers better visibility—they just want it to be a two-way street. If publishers are expected to expose their inventory data, why aren’t agencies held to the same standard with their buy-side margins?
Measurement & Business Outcomes: Keeping Score Where It Counts
Buyers don’t just want metrics—they want metrics that matter.
“A click-through rate has never been truly correlated with a business outcome,” said Estes. And she’s right. CFOs aren’t signing off on budgets because of CTRs. They want to see a direct link between ad spend and revenue.
For publishers, this means:
- Moving beyond impressions and CPMs to metrics that align with business outcomes.
- Understanding audience behavior beyond surface-level engagement.
- Proactively sharing insights that connect content consumption to purchase intent.
Sellers who fail to provide this will end up as just another player on the court, but not the one making winning shots.
The Sell Side’s Next Move: Time to Run the Offense
The buy side has spent years tightening its grip on programmatic, pushing for preferred paths that cut out direct publisher relationships. But publishers are no longer willing to just play defense. The momentum is shifting from reclaiming control of SPO to redefining how they sell their data and ad products.
It’s time for publishers to stop reacting to the buyer-driven game and start calling their own plays. As the Sell Side Summit discussions revealed, sellers already have the strategies and solutions to do just that. And, the ones who start calling the shots will thrive.