By Forty to 50 percent supply chain cost reduction. That's what PubMatic (Nasdaq: PUBM) is claiming from early AgenticOS campaigns run through its new partnership with Untapped Growth, a media buying collective representing 20 independent agencies. The press release dropped March 25, and it's loaded with the kind of numbers that make a CMO lean forward in their chair: 40% more impressions, 30% lower eCPMs, 87% faster campaign setup, 70% faster troubleshooting.
I've seen this pitch before. Let's check the receipts.
The deal, stripped down
PubMatic and Untapped Growth are giving independent agencies the ability to deploy proprietary buyer agents directly inside AgenticOS, PubMatic's agentic advertising platform launched at CES in January 2026. Agencies submit campaign briefs through an LLM-powered interface in natural language, specifying audience parameters, budget, timing, and brand safety requirements. AgenticOS returns recommended audiences and curated inventory packages. The trader approves, provides creative, and activates.
Campaigns run through PubMatic's Activate, a direct bidder built natively on the sell side that launched in 2023. The pitch: no DSP required. One connection gets you access to billions of daily impressions across CTV (including 28 of the top 30 streamers, according to PubMatic), mobile, and online video, plus 250+ data partners.
"Through this partnership with PubMatic, member agencies now have the ability to activate high-performing agent-driven campaigns at scale, delivering premium inventory with greater efficiency, and without the added operational tax," said Brendan Clifford, co-founder and managing partner at Untapped Growth, in the press release.
Kyle Dozeman, PubMatic's chief revenue officer, was more pointed: "Most recent agentic implementations don't solve the fundamental supply chain problem. They simply replace manual hops with automated ones."
That's a spicy claim from an SSP that is, let's be honest, trying to eat the DSP's lunch.
Where the numbers don't add up
Here's where my vendor scorecard gets interesting. The press release claims 40-50% supply chain cost reduction and 87% faster campaign setup from "early AgenticOS campaigns." But an Adweek report published the day before tells a different story: a third agency testing AgenticOS (not an Untapped Growth member) saw an 82% reduction in buy-side costs and close to 90% reduction in campaign setup time.
So which is it? 40-50% or 82%? 87% faster or 90% faster? The deck said one thing, but the exclusive said another.
The answer, most likely, is that these are different campaigns measured differently, which is exactly the problem. When your performance claims swing by 30+ percentage points depending on which press hit you're reading, you don't have a benchmark. You have a brochure.
A few questions I'd want answered before putting budget behind this:
- What's the control group? Are these numbers compared to a full-stack DSP workflow? A managed service? A self-serve seat with a junior trader? The baseline matters enormously, and neither PubMatic nor Untapped Growth has disclosed it.
- Who verified these results? Every number in both the press release and the Adweek piece comes from PubMatic itself. No third-party measurement partner is named. No independent audit.
- How many campaigns are we talking about? PubMatic says 250+ agentic deals have been transacted since the January launch. That's across all AgenticOS partners, not just Untapped Growth. For this specific partnership, only two Untapped Growth agencies are "expected to go live shortly," according to Adweek. Which means most of these headline numbers come from pre-launch testing with a sample size we can only guess at.
What "bypassing the DSP" actually means here
Let's talk about the structural claim, because it's the interesting one. PubMatic is positioning AgenticOS + Activate as a way to collapse the buy-side and sell-side into a single layer. Harry Tong, PubMatic's director of sales engineering, told Adweek that "SSP, DSP terms are already a bit obsolete."
Is that true? Partially. Activate does let buyers transact directly on the SSP without a separate DSP integration. That removes a tech fee layer, and for indie agencies running $500K-$2M monthly across a fragmented vendor stack, that fee compression is real and meaningful. The "tech tax," as Clifford calls it, can eat 15-30% of working media depending on the supply path.
But "bypassing the DSP" doesn't mean bypassing demand-side decision-making. It means PubMatic is doing the demand-side decision-making for you, inside their own infrastructure, using their own agents. You're not removing an intermediary. You're consolidating two intermediaries into one that happens to own the supply. Does that create better alignment? Maybe. Does it create a conflict of interest where your buying agent's infrastructure is owned by the seller? Obviously.
PubMatic's counter would be that transparency and control are built into the workflow, with real-time delivery data surfaced directly to the agency. Fair enough. But "trust us, we show you the data" is different from "here's an independent verification of that data."
The real opportunity (and it is real)
Here's where I stop being skeptical, because the underlying thesis has merit.
Independent agencies have been structurally disadvantaged in programmatic for years. They lack the volume to negotiate favorable DSP terms, they don't have the engineering teams to build custom integrations, and they often end up paying more for worse inventory than holding company desks running on the same platforms. Untapped Growth exists precisely because of this gap, aggregating buying power across 20 agencies to unlock pricing and access that no single indie could get alone.
Layering agentic automation on top of that collective buying power is a smart play. If (and it's a big if) the performance claims hold at scale, an indie agency trader who currently spends hours per campaign on setup, trafficking, and troubleshooting could redirect that time toward strategy and client growth. PubMatic says the system handles audience discovery, inventory curation, and optimization signals automatically. For a five-person media team trying to compete with a holding company's 50-person programmatic desk, that is a genuine capability unlock.
And the protocol layer matters. AgenticOS is built on MCP and AdCP protocols, which means (in theory) interoperability with other agentic systems. That's a meaningful differentiator from closed-loop alternatives. Whether that interoperability actually materializes at scale is another question entirely.
Verdict: the thesis is strong, the execution is early, and the proof points are self-graded.
What to do Monday morning
If you're a media buyer at an independent agency, don't rip up your DSP contracts yet. The Untapped Growth partnership is barely live, with only two member agencies expected to launch shortly.
What you should do: get on PubMatic's Agentic AI Acceleration Program waitlist if you haven't already (nearly 100 brands, agencies, and streamers have applied, according to PubMatic). Run a parallel test, same campaign brief, same budget, same KPIs, through both your existing DSP workflow and AgenticOS. Compare actual eCPMs, not promised ones. Compare actual working media ratios, not deck slides.
If PubMatic's numbers hold up under controlled comparison, this could be the most meaningful supply path optimization play for indies in years. If they don't, you'll have the data to say so.
Either way, you'll have receipts. And in this business, that's what matters.
Mira Castellano covers ad tech for The Daily Vibe.
