RTBDAY ’25 highlighted the power of partnerships in navigating AI, measurement, ecommerce, and privacy shifts. Here are seven takeaways publishers need to know now.
While RTBDAY’25 may have been a buy-side event, there were many takeaways for the sell-side. And if there was one theme weaving through the day that might have been subtle, it was that no one is winning alone anymore.
From AI’s growing influence on media buying to ecommerce flexing its muscle and the ongoing game of measurement musical chairs, the event underscored how collaboration is no longer a nice-to-have but a necessity. RTBDAY’25 brought in heavy hitters from eMarketer, Google, Dotdash Meredith, and top retail brands to lay out the next chapter in digital advertising.
Success in 2025 is about working together—whether it’s publishers teaming up with brands, data partnerships taking center stage, or AI bridging the gap between creative and performance. Here are six themes that emerged from the day.
Takeaway 1: Ecommerce Is Still the Ad Spend MVP
Retail is still running up the score on digital ad spend, and eMarketer’s outlook is bullish. Ecommerce ad spending is projected to grow 12.5% in 2025, and the U.S. market is expected to hit $1.3 trillion.
While Amazon still owns 41% of ecommerce sales, the real story is the growth happening beyond the retail giant. Players like Walmart, Target, and Instacart are ramping up their media networks, and non-Amazon retailers will drive 57% of incremental ecommerce sales next year.
Allegro, often called the Amazon of Central Europe, highlighted how creative excellence is now a performance lever for its RMN. It shows that blending brand-building and lower-funnel strategies drives results.
For publishers, this means retail media and commerce-driven ad strategies will only become more valuable—not just for product ads but also for upper-funnel brand-building campaigns that need trusted, premium environments. Partnerships with brands and RMNs looking to connect creative, performance, and data will be critical. Publishers who position themselves as collaborative partners—offering audience insights and flexible, innovative solutions—will stand out as this spend accelerates
Takeaway 2: Measurement Remains a Work in Progress
Incrementality testing, marketing mix modeling (MMM), and multi-touch attribution (MTA) all got airtime as brands like Revolve, Coach, and Allegro shared their struggles to crack the measurement code.
The consensus? There is no silver bullet. “GA4 wasn’t it,” shared Ryan Pabelona, VP of Performance Marketing at Revolve. The transition to Google’s latest analytics platform was bumpy, and the changes to attribution models left channels looking different overnight. “We waited until the last minute to switch,” he admitted, adding that the experience underscored a critical lesson: publishers and advertisers can’t rely on a single source of truth.
For Revolve, that meant building internal measurement baselines that hold steady regardless of vendor shifts and leaning into incrementality testing as a check against GA’s readout. “Just measure it some other way,” Pabelona said. “That way, you have a more consistent way to look at things.”
Publishers should expect advertisers to push harder for performance validation across multiple data sources—and be ready to demonstrate their value from brand lift at the top of the funnel to sales-driven impact at the bottom. More direct conversations around data access, custom reporting, and collaborative testing will be the norm.
Takeaway 3: AI Is Changing Creative and Performance Dynamics
AI has moved from buzzword to action item. Retailers like Revolve are already leveraging AI-powered tools to create scalable product imagery, while Coach is tapping AI for audience insights to refine creative direction. But AI’s real power emerges when brands and publishers work together to align creative production, audience insights, and media environments.
For publishers, that means moving beyond simply running AI-powered creative. The opportunity is to partner with brands on creative testing, dynamic optimization, and audience refinement—combining publisher data and context with brand AI-driven assets for better performance.
AI works best when paired with human creativity and strategic partnerships. Publishers who are collaborators in this process, not just media sellers, will have the edge.
Takeaway 4: Privacy is Pushing Contextual Targeting to the Forefront
Lisa Martinez Gilpin, Director Global GTM, Privacy Sandbox, shared the latest update on Privacy Sandbox and the slow farewell to third-party cookies, emphasizing that user choice will shape the future timeline. Publishers like Dotdash Meredith are leaning into contextual targeting as a privacy-safe solution that aligns with their content-driven approach.
Contextual is delivering results, but it’s not a one-size-fits-all fix. The road ahead for Privacy Sandbox is paved with uncertainty. Google is moving, but brands and publishers must test, learn, and iterate to find what works at scale. “I think the closer that publishers, ad tech partners, and marketers actually work together, along with our platform and technology partners, the better off we all are,” said Lindsay Van Kirk, SVP and GM, D/cipher at Dotdash Meredith.
Takeaway 5: First-Party Data Moves Front and Center—But Control and Scale Demand Collaboration
While contextual targeting and privacy-first ad models are gaining traction, first-party data is emerging as the foundation for future success. But it’s not a silver bullet. Publishers like Dotdash Meredith leverage it effectively, but brands want more, and even the most prominent players face scale and consistency challenges. Owning your data is table stakes, but scale is the genuine hurdle.
Ryan Pabelona from Revolve and other brand leaders clarified that advertisers want audience consistency and performance across platforms, not siloed datasets. That’s why clean rooms, data collaboration hubs, and audience-matching partnerships are increasingly important. These tools let publishers pool data securely, helping advertisers connect the dots without sacrificing privacy.
Retail media networks like Walmart and Target leverage their own first-party data power, and publishers risk being left behind unless they collaborate to offer buyers cross-platform solutions.
The next phase is about pooling strengths—publishers, advertisers, retail media networks (and even platforms) finding ways to share data responsibly. Collaboration is the only way to make first-party data truly scalable and valuable.
Takeaway 6: Brands Want Partners, Not Just Vendors
If brands had one underlying message at RTBDAY ’25, they would want and need partners, not just places to run ads.
Pabelona from Revolve spoke about building internal measurement consistency and leaning on external partners for testing and validation. Coach is tapping AI for creative insights but needs publishers who can bring audience data and flexible, creative solutions to drive tangible outcomes. Allegro’s creative performance success showed that brands are blending upper-funnel and lower-funnel work—and they need media partners who get both sides of that equation.
The ask is more significant than just impressions. Brands want publishers who will sit at the table with them, helping them figure out measurement gaps, test new formats, and align creative with performance goals.
For brands, it’s about more than delivering reach; they want to solve their business challenges. For publishers, this means a mindset shift. It’s time to shift from just selling inventory to offering solutions, from passive supplier to active collaborator.
Takeaway 7: Resilience Requires Revenue Diversity
If there was a cautionary note hidden in the messages from RTBDAY ’25, it was that publishers shouldn’t depend on any single revenue stream, traffic source, or platform partner. Overdependence—whether on Google for traffic, Amazon for commerce partnerships, or any single demand partner—can leave you exposed.
As Jaysen Gillespie, VP of Analytics and Product Marketing at RTB House, warned, “Make sure no one’s got you by the throat. If 60% of your traffic or revenue is coming from one source, you’re vulnerable.”
While data partnerships and brand collaboration are critical, so is building a business model that isn’t over-leveraged in one area. Direct-sold deals, programmatic, retail media partnerships, branded content, affiliate partnerships, and commerce must work together.
Thriving in 2025 isn’t just about selling inventory—it’s about layering revenue streams and flexing as the market shifts.
No One Wins Alone
The biggest lesson from RTBDAY ’25? The era of isolated strategies is over. Whether it’s AI-driven creative, privacy-first audience solutions, or proving performance without cookies, the future belongs to those who work together.
Publishers, advertisers, and platforms must forge deeper partnerships, shared data strategies, and cross-functional collaboration to keep up with the shifting ad tech landscape. In 2025, the smartest players won’t just optimize alone—they’ll build, test, and win together.