When one hears “agent” lately, one routinely thinks “AI” – however that’s not what this story is about. This can be a story about how businesses are dropping what makes them brokers – as in, placing the pursuits of their shoppers first.
Advert company holding corporations are among the many most adaptable companies on the market. In recent times, holdcos like Publicis, WPP and Omnicom-IPG have stretched our notions of what an company enterprise even is precisely.
For instance, holdcos have acquired consultancy practices, that are a pure add-on for managed service-minded companies. They’ve additionally added subscription software program, market knowledge gross sales, advert tech CPM charges and different income strains. These new enterprise fashions can pressure the relationships between large businesses and their shoppers.
However nowhere is that pressure extra pronounced than with principal-based shopping for, which is now a fast-growing, multibillion-dollar income stream for holdcos.
Rebates: Identical because it ever was
It’s been virtually 10 years for the reason that Affiliation of Nationwide Advertisers and auditing agency K2 Intelligence printed a bombshell report on company rebate practices. The report documented businesses gathering money kickbacks from large media sellers primarily based on spend quantity – however these refunds didn’t make it again to shoppers.
Though the report felt explosive on the time, the identical factor may very well be printed at the moment and be equally true. If something, the practices described by the ANA in 2016 have develop into virtually acceptable. Direct rebates stay prohibited within the US, as they have been a decade in the past, however are commonplace elsewhere, together with Europe.
Companies have merely gotten craftier, recreating rebate economics by means of principal-based buying and selling and different types of advert credit score allocation that skirt the foundations.
Why now?
But when media rebate practices aren’t new, why is that this boiling over once more in 2026?
Just a few notable issues occurred.
First, a former WPP company chief named Richard Foster filed a wrongful termination lawsuit alleging he was let go final 12 months after elevating objections to the holdco’s media rebate practices. WPP’s counter-filing made public a 2024 memo penned by Foster revealing GroupM’s principal media income had hit greater than $1 billion.
Second, as businesses broaden into software program, advert tech and knowledge gross sales, they’re trespassing on the turf of distributors and companions as hybrid client-competitors.
The Commerce Desk, for example, has at all times taken nice care to place itself as an ally of businesses – nevertheless it appears to attract the road at principal media.
Simply this week, after information broke of a rift between Publicis and TTD over a marketing campaign auditing request, TTD CEO Inexperienced responded in a LinkedIn publish calling out businesses “who wave the flag of transparency publicly, however run from it in observe as they arbitrage within the inefficiencies of programmatic.” He particularly cited principal-based media because the arbitrage in query.
And through TTD’s full-year 2025 earnings name final month, Inexperienced informed buyers that he doesn’t assume businesses are “doing pretty much as good of a job representing their shoppers as they might.” He was referring to principal-based shopping for after being requested about latest information that WPP and Dentsu had pulled again from OpenPath, TTD’s direct-to-publisher integration.
“I’m not shocked that some folks wish to flip [OpenPath] off in the event that they discover methods to receives a commission in distinctive methods,” Inexperienced stated.
“Distinctive methods” like these cited in Foster v. WPP, which affords a uncommon view into how the holdco thinks concerning the observe of principal-based media and the true scale of that income line.
In WPP’s aforementioned counter-filing, the 2024 memo authored by Foster, the previous exec wrote that, in 2023, GroupM exceeded $1 billion in international internet gross sales for “non-product associated earnings,” which is WPP’s innocuous-sounding identify for principal-based media. (At different occasions, the observe was additionally internally referred to euphemistically as “proprietary media buying and selling” and “buy threat media offers.”)
In accordance with the memo, non-product-related earnings was forecasted to develop 15% in 2024, even whereas WPP’s internet income was on a slight decline.
However is principal media truly unhealthy?
Drama apart, it’s truthful to wonder if principal media buying and selling is an precise downside.
The ANA, for instance, isn’t categorically opposed.
“[Our perspective is that marketers need to take a proactive stance in educating themselves on the benefits and challenges of principal media as well as the internal governance requirements,” ANA group EVP Bill Duggan told AdExchanger in an email.
Without clear contractual permissions and guardrails in place for things like spending caps and audit rights, he added, principal media is “buyer beware.”
In other words, agency holdcos have many different business models nowadays, and this is just one more way to get paid. Brands need to go in with their eyes open.
But one could also argue that principal media trading is a different kind of beast altogether, because it fundamentally misaligns incentives for agencies as true agents for their customers.
And all of the holdcos understand full well that principal trading isn’t a practice to be particularly proud of.
Last month, a Barclays Bank analyst asked Publicis CEO Arthur Sadoun why the holdco’s principal media revenue remains in the low single digits. “It is not a strategic priority for us,” Sadoun responded. “We are not the biggest player by far.”
Publicis’ principal media revenue is undisclosed, and we only know what WPP makes thanks to a disclosure in a lawsuit. The only holdco that unashamedly cites its principal media revenue is Omnicom.
“It’s a product we’ve had for a long time. It’s a product that continues to grow, and I can see very clearly that it’s going to continue to grow into the future,” Omnicom CEO John Wren said during the company’s Q2 2025 call in July.
“Everybody else that you speak to in the industry doesn’t tell you the truth,” he added. “It is what it is … it is a product.”
In 2025, Omnicom’s principal media revenue grew by $388 million to a total of $1.4 billion.
What’s next?
But despite the increased scrutiny and wariness of brand marketers, don’t expect the principal-trading trend to slow down.
GroupM CEO Brian Lesser told WPP investors last month that marketers, especially those “trying to navigate” addressable TV ads, social media and retail media, are under pressure to prove performance. Principal media trading offers a cheaper route to that inventory, Lesser said, “and they are asking us for more, frankly.”
On the other hand, WPP’s legal disclosures reveal that none of its top 20 biggest clients participate in principal media – despite the fact that many of WPP’s largest brand accounts are themselves the purveyors of principal media deals on the supply side, including Paramount, Comcast, Uber, Amazon, Google and Sony.
These brands stand to gain the most from principal media, which rewards pure volume. They’re also very knowledgeable about the practice, which is perhaps one reason they avoid it when they have their buy-side hat on.
Regardless of any taboo, however, the practice won’t disappear. It’ll just morph.
After all, principal-media trades produce some of the highest-margin revenue for agencies right now.
Although holdco leaders will continue trying to keep themselves out of the principal media spotlight, their incentives are to pursue that revenue as hard as they can behind closed doors. When bankers have asked about principal media buying on recent holdco earnings calls, it hasn’t been out of concern. Investors want to see more principal media revenue.
So how might trends like rebates and principal media buying evolve?
Foster himself proposed alternatives, like by spending on ad commitments or investing upfront in brand-backed content production for streaming media platforms, citing the likes of A+E, TikTok and Roku. Those investments would yield ad credits or exclusive first-look ad opportunities that could be repackaged by GroupM.
In other words, the mechanics may change, but the incentives don’t. Principal media is just the latest expression of a familiar instinct inside of the holding companies. If there’s a new way to get paid, they’ll find it – and they’ll scale it.
