Publishers are losing search traffic as consumers flock to generative AI answer engines. The trend is forcing pubs to get the most out of the traffic that still comes to their sites.
But publishers are also losing visibility into the traffic they still have as users take measures to protect themselves from being tracked online.
Audiences that reach publisher sites but leave little to no trace in analytics are referred to as dark traffic. Typically, these users have their referral data stripped, and they use VPNs and ad blockers to obscure their identity and limit their exposure to cookies and tracking pixels.
The result is an incomplete picture of audience size, engagement and monetization potential at a time when every pageview counts.
At Penske Media Corporation (PMC), shining a light on dark traffic is part of a broader recalibration of how the publisher thinks about audience growth, attribution and long-term sustainability. To boost its ad sales efforts, PMC worked with ad block recovery platform Ad-Shield to devise new strategies for measuring the dark traffic coming from its direct channels.
Owned audiences, unclear attribution
For PMC, today’s shifting online traffic patterns have clarified where long-term value actually sits, said Dustin Park, the company’s VP of revenue operations.
It’s not just the expansion of zero-click search or social media platforms deprioritizing outbound links that’s harming publishers like PMC. Ad blocker usage has surpassed 1 billion users globally, driven increasingly by network-level tools that bypass traditional detection, according to a recent dark traffic study by Ad-Shield. For pubs, that means a larger share of human traffic is effectively invisible to both analytics platforms and monetization systems.
As a result of these challenges, PMC has leaned into direct relationships—newsletters, subscriptions, live events and repeat site visits. These users tend to engage more consistently, share data more willingly and are less influenced by the volatility of platform algorithms.
“The changes in referral traffic have reinforced something we already believed—that owned audience relationships are the most durable asset a publisher can have,” Park said.
But even those direct channels bring a share of dark traffic.
The impact varies across PMC’s portfolio, which includes a mix of B2B publications, like Variety, and general interest brands, like Rolling Stone. The trade publications are more likely to be accessed through corporate or school networks, where ad blocking is common, Park said, while consumer-facing properties see more VPN and ad blocker usage overall.
In both cases, traffic may appear in PMC’s analytics systems labeled as “direct” or go partially untracked.
Modeling these dark traffic pools against known users is the first step toward filling the knowledge gap.
“Full attribution for these users is frankly an unsolved problem industrywide,” Park said. “But you can get meaningfully closer by modeling based on your full audience.”
Turning hidden audiences into revenue
Once dark traffic audiences are better understood, the next question is how to engage them without undermining the user experience.
PMC first worked to quantify the size of its dark traffic audience before exploring ways to reconnect with those users through “consent-based messaging” and lighter ad experiences, according to Park.
“The real opportunity is in reestablishing what we’d call a fair value exchange,” Park said. “Many of these users aren’t opposed to supporting the publishers they read. They’ve just opted out of an experience that felt intrusive.”
Meanwhile, a growing share of dark traffic is driven not by deliberate user choice, but by infrastructure such as corporate security settings, privacy tools or default browser protections. In many cases, users may not even realize ads are being blocked. This reality has created space for technologies that restore visibility and monetization without relying on traditional adblock recovery tactics.
Companies like Ad-Shield are working to make those traffic pools that inadvertently opted out of ads measurable again and to reconnect them to publishers’ ad stacks. PMC recently partnered with Ad-Shield to recover its lost audiences.
According to Ad-Shield, publishers using its platform have seen audience increases of 5–20%, with significant gains in recovered revenue. While results from using the solution vary, the broader takeaway is that some “lost” revenue was never actually lost, but simply never counted by publishers’ existing systems.
The added visibility provided by Ad-Shield has expanded PMC’s available inventory for direct-sold campaigns and provided a more accurate view of its total audience reach.
Having a better sense of its audience size has also changed how PMC evaluates the earning potential of its traffic channels.
“If a meaningful slice of your audience is invisible to your analytics and your ad stack, you’ve been systematically undervaluing the channels that reach them,” Park said.
Once dark traffic is factored in, direct and owned channels often perform better than existing attribution models suggest, Park added. That, in turn, strengthens the publisher’s sales pitch to advertisers.
“When you can finally see the full audience those channels are already delivering,” he said, “the investment thesis for building on them becomes much clearer.”
