Shai Luft.
The recent coverage around Omnicom’s principal media buying model has pulled back the curtain on a practice that raises serious questions about transparency, neutrality and client-first thinking in media agency land.
For those unfamiliar, “principal media buying” is when an agency buys inventory in bulk from publishers or platforms, often at discounted rates and then resells it to their clients - typically at a markup. While this might sound like a smart commercial move on the surface, it introduces a glaring conflict of interest: the agency becomes both the seller and the buyer, motivated not solely by delivering the best results for the client, but by maximising their own margins.
It blurs the fundamental role of a media agency. Are they acting as strategic advisors who guide clients toward the right media choices? Or are they operating more like media wholesalers, with a vested interest in moving specific inventory?
The real issue here isn’t just that agencies profit from arbitrage - it’s that clients are often left in the dark about how much. The lack of transparency is staggering. Marketers working under the assumption that their agency is buying media in their best interest may never realise that recommendations are shaped more by internal revenue targets than campaign performance.
Despite industry-wide lip service to the principles of trust, transparency, and neutrality, this model contradicts all three. It’s one thing to markup media when value is being added - for example, through data layering, innovation, or executional excellence. It’s another thing entirely when the markup exists purely to pad margins, hidden behind opaque commercial terms.
Principal buying also shifts the agency’s incentives in dangerous ways. When an agency carries the risk of unsold inventory, it becomes motivated to “push” certain placements - regardless of whether those placements are aligned with the client’s goals. That’s not strategy, that’s salesmanship.
It’s no coincidence that principal models are often underpinned by volume deals or annual spend commitments with specific publishers or platforms. And while these deals may secure discounted inventory for the agency, they also anchor decisions to predefined targets, rather than campaign-specific needs. That’s a fundamental misalignment. Clients hire agencies for bespoke thinking, not cookie-cutter plans driven by back-end deals.
The implications go beyond ethics, they impact effectiveness. In today’s media environment, where programmatic channels allow us to target with incredible precision, success hinges not just on how much reach we get, but who we reach. A cheap CPM might look great on paper, but if it’s not hitting the right audience at the right moment, it’s wasted spend.
That’s why marketers should increasingly look at effective CPM - how much it costs to reach a qualified target within the desired segment, rather than chasing low headline rates that sacrifice audience quality. Principal models often rely on inventory that’s easier to acquire in bulk, but harder to align with a nuanced strategy.
In a time when marketing budgets are under more pressure than ever, the temptation to cut corners or drive efficiency through scale is understandable. But sacrificing integrity in media buying is a short-term play with long-term consequences. It erodes trust, limits effectiveness, and ultimately damages the agency-client relationship.
This moment should serve as a wake-up call to marketers. Ask the hard questions. Where is your media being bought? Is your agency financially incentivised to favour certain platforms or publishers? Are recommendations being made with your business outcomes in mind - or theirs?
None of this is to say that principal media buying can never work. In some cases, it may offer genuine benefits to clients when handled with full transparency and consent. But in most cases, the lack of disclosure, coupled with misaligned incentives, makes it a problematic default. It invites suspicion and undermines the credibility of agencies at a time when trust is already a scarce resource.
As an industry, we need to draw a clearer line between media buying and media selling. Agencies should not be wearing both hats. Our role is to help clients navigate a complex media ecosystem with clarity, objectivity, and a relentless focus on outcomes - not on protecting our own inventory exposure.
There’s also a reputational risk that can’t be ignored. As more marketers become aware of these practices, the agencies involved risk alienating the very clients they’re trying to serve - and in a competitive landscape, that loss of trust can be fatal.
This moment highlights the value of independent media agencies that are free from these conflicts - agencies that don’t have hidden incentives or undisclosed commitments influencing their recommendations. Independence doesn’t just mean being smaller or scrappier; it means being structurally set up to act in the best interest of the client, always.
It also means being truly media-agnostic. That’s not just a buzzword; it’s a way of working. It means choosing platforms based on performance, not profit. It means assessing inventory based on alignment with audience goals, not leftover commitments. And it means putting strategy before scale, every time.
Transparency isn’t a nice-to-have. It’s the bedrock of every good client-agency relationship. And when that transparency is compromised, the entire partnership is put at risk. Clients shouldn’t have to wonder if the media plan in front of them is what’s best for their business, or just what’s best for the agency’s margins.
Marketers deserve better. They deserve partners who will challenge them, support them, and act as stewards of their budgets with care and integrity. The good news? Those partners exist. And many of them are proving that you don’t need to cut deals behind closed doors to deliver real, measurable results.
At a time when the marketing landscape is evolving faster than ever, trust will be the most valuable currency. Agencies that honour it will thrive. The rest? It might be time for a reckoning.
Shai Luft, co-founder and COO at Bench Media