The Guardian US announced its adoption of The Trade Desk’s OpenPath at the AdMonsters Sell Side Summit in Fort Lauderdale last month. We conducted a follow-up interview with Sara Badler, chief advertising officer for North America at The Guardian US to find out how the product streamlines its programmatic buying.
The programmatic supply chain is oversaturated and complicated. The industry has heard this many times, and there are many reasons why. The industry is plagued by duplicated bid requests and auction waste. There are too many intermediaries. The list goes on.
Publishers experience the fallout from these issues firsthand. But some, like The Guardian US, are taking action. In March, The Guardian US partnered with The Trade Desk to use its supply-path optimization (SPO) tool OpenPath, which gives advertisers direct access to publisher inventory.
“We’re not the first to do this, but for us at The Guardian, it’s a big step as we expand our programmatic strategy across the board—especially in the US, where we’re making a strong push,” said Sara Badler, who joined late last year as chief advertising officer for North America.
According to David Strauss, VP of revenue operations and strategy, The Guardian “wants an auction where whoever wants to pay the most for an impression wins.”
“OpenPath helps us create a fair, transparent ecosystem where everyone has an equal opportunity to compete for our inventory,” said Strauss, who dropped the announcement on stage at Sell Side Summit Fort Lauderdale last month.
Badler views the current programmatic landscape pragmatically, noting that SSPs and DSPs have become almost indistinguishable—just mechanisms to help publishers and marketers access inventory.
The Guardian’s implementation of OpenPath is a critical part of the evolution of its programmatic strategy to create high-quality advertising experiences while also maximizing yield.
The Integration Component
But Badler described the OpenPath integration, which took several months to complete, as more complex and time-consuming than expected, including untangling internal issues, addressing external challenges and navigating contract negotiations.
“The Guardian is choosy about who it partners with. All partnerships must be strategic and optimal,” Badler said, adding that integrations require a lot of internal and external communication.
“We are very excited that it is complete and what it will bring in the upcoming quarters,” she said.
Despite the challenges, Badler prioritized the OpenPath integration early in her tenure at The Guardian US and views The Trade Desk as a strong partner.
When publishers implement OpenPath through a server-to-server integration, it gives The Trade Desk direct access to inventory without relying on SSPs. This eliminates redundant auction hops, reducing both latency and carbon emissions. While OpenPath can integrate with Prebid (which supports both client- and server-side setups), server-side OpenRTB is the primary method for direct publisher integrations.
“I would describe ours as similar to a client-side integration,” said Badler. “We are working with [The Trade Desk] on our page to provide value in monetizing our overall yield.”
This model parallels the IAB Tech Lab’s Trusted Server framework, introduced in March, which also promotes server-side auctions controlled by publishers to curb data leakage and mitigate browser restrictions, like Chrome’s Privacy Sandbox.
However, while OpenPath is a proprietary solution operated by The Trade Desk, the Tech Lab’s Trusted Server is an open-source initiative.
The Guardian’s Pragmatic Bet on OpenPath
Some in the industry were initially skeptical of OpenPath’s impact on SSPs, fearing disintermediation. But early adopters, including The Guardian, have reported incremental revenue gains without disrupting existing SSP relationships.
Direct access to advertisers with OpenPath is a win-win in Badler’s view. The Guardian’s programmatic revenue in the US increased over 25% so far in 2025 compared to this time last year.
But OpenPath and The Trade Desk are not without their critics.
For instance, when The Trade Desk first launched OpenPath in 2022, some worried whether a DSP would work in the best interest of publishers. Industry consensus was that the benefits outweighed the concerns, yet some skeptics remain.
The Guardian, however, appears happy. As Strauss put it at Sell Side Summit, “We’ve seen tremendous success with them, and after three weeks.”
Badler said The Guardian US is seeing an overall increase in CPMs and starting to form direct relationships with advertisers through private marketplaces.
“We have seen an overall increase in spend from TTD holistically,” said Badler. “It was important to us that we did not see spend simply move from other SSPs to OpenPath.”
Badler emphasized that, despite The Trade Desk’s recent quarterly challenges, it remains one of the few ad tech partners with a truly global footprint that’s comparable to The Guardian’s international presence.