How Advertisers Can Tap a $175B Opportunity By Breaking Away from Walled Gardens

This post was created in partnership with Outbrain

Consumers are wandering from “walled gardens” like Google and Meta to the open internet’s sprawling landscape of streaming, audio, and news platforms. Advertisers who follow them can unlock a $175 billion opportunity.

To get there, publishers will have to “break down walls” that are holding back brands from tapping the open internet’s potential, an all-star roundtable revealed at an ADWEEK House event co-hosted by Outbrain at CES 2025 in Las Vegas this month.

“I think there is one fundamental issue that is holding back the open Internet. And that issue is attribution,” Matthew Scott Goldstein, an independent analyst, told the gathering. “Targeting is pretty simple, but if you can’t measure and you can’t attribute, advertising dollars will keep going down.” Amazon and Google, the two biggest walled gardens, “have their own measurement built in. They’re like batters calling their own balls and strikes.”

Because the open internet still carries a tinge of the “wild west”, publishers also need to change perceptions that walled gardens are the sole “bastions of trust and safety” for brands, said Danielle Betras, VP, Partnerships & Portfolio Development at The New York Times.

“We’ve done research. Stagwell did research. And we saw that brand safety is not affected across news, even hard news,” she said. “It’s the same impact as when you show up around sports. I feel like as an industry, we have the data and we have a rational perspective on this. What we don’t have yet is support or even just bravery from advertisers and brands to act on that and to behave differently around it.”

Publishers on the open internet should start pushing back with their own metrics―like one around attention, said Stephanie Mehta, CEO of Mansueto Ventures. “Walled gardens do an amazing job of maximizing impressions. But a majority of our Product Council, which includes brands and agencies across categories, told us they were building attention strategies for 2025. So we’re offering an Attention Metric that’s easy to measure. Attention is something that high-quality content can command.”

David Kostman, CEO of Outbrain, agreed. “Attention is a great way to measure incremental value. There’s no doubt in my mind that a person pays more attention when they are in authentic trust. No matter which political side you are, when you spend the time reading something, the attention metrics are great. That’s something traditional publishers are great at doing. Again, it’s not going to solve the attribution question, but it is a way to show value.”

For marketers willing to make the leap, the open internet also offers “authenticity, trust, more freedom, and more room for innovation,” said Chloe Depiesse, head of the Havas Innovation Lab at Havas. “With the walled gardens, you play by their rules and their ad formats. If you’re lucky, you become part of an alpha or beta program. But with the open internet, the world’s your oyster. You can talk to the platform, talk to the publisher, and create a new kind of experience.”

Platforms and publishers should also amplify how brands can reap added value from the open internet, said Richard Hartell, North America CEO of EssenceMediacom US.

“Ask marketers, ‘What don’t you get from the walled gardens? Maybe you can’t necessarily get a trusted brand context that matches your brand, or certain parts of utility and functionality that do not exist,” he said. “As a publisher, I can say, ‘Hey, agency people, there might be some measurement and attribution problems, but I can give you innovation you can’t get on Facebook, Google, or Amazon.”