Just to best understand a rather new term, "proprietary  media"....Proprietary media (or inventory media) is ad space a media agency buys upfront with its own funds, acting as a principal rather than an agent. The agency owns this inventory, often reselling it to clients at a markup without disclosing the original price or allowing audits. Key synonyms include inventory media, principal-based buying, or principal media. Another reason, why I always have liked calling on local-direct clients and saving them lots of unnecessary revenue losses: Philip Jay LeNoble, Ph.D.

Commentary

Are You an Advertiser -- Or Just Your Agency's Favorite Customer?

• by Maarten Albarda , Featured Contributor, 4 hours ago

If there’s one thing that never changes, it’s the industry's ability to dress up a potential conflict of interest as a "strategic solution” or a “competitive advantage.”  Proprietary or principal media is the current poster child for this.

Lately, many agency media pitches include these "exclusive" bundles. The story is compelling: better pricing and increased agility. And: “It’s the media you would buy anyway, but now we have bought it for our clients and you can get it at our exclusive price.”  But let’s be honest: When your advisor is also the seller, the line between "best for the client" and "best for the agency’s margin" becomes a mess.

The U.S. market is leaning into principal media hard. Recent forecasts for 2026 suggest proprietary media will continue to be a massive revenue engine for agencies as they look to offset declining traditional margins. We’re seeing a "K-shaped" media economy where the top holding companies are leveraging their massive scale (like the recently merged Omnicom and IPG) to obtain and market proprietary bundles in fragmented spaces like Retail Media and CTV.

The ANA has been sounding the alarm on transparency for years, and while we’ve seen some wins like advertisers significantly tightening the transparency and media audit language in their contracts, there is still a massive $26.8 billion lost annually to inefficiencies.

That’s because many advertisers have not addressed the various elephants in the room. Proprietary media, mixed in with standard media buys and shielded by limited audit rights, makes it nearly impossible to tell if what you pay is what you should be paying -- or even should be buying in the first place.

ISBA in the UK is what the ANA is in the U.S. It has just released a major governance paper on the topic of proprietary media, because U.K. advertisers are seeking ways to push back.

Don’t get me wrong, and I’ve said this before: Proprietary media isn’t inherently "evil." It can offer genuine value, especially in accessing premium inventory that’s hard to get. But it’s a tool that requires a very sharp set of guardrails. Without them, you’re not an advertiser; you’re just a customer of your agency’s inventory business.

So if you’re going to play in this sandbox, don’t do it on the agency's terms, but create your own set of rules, enforced by third-party audit rights. For instance, create an internal strategy that defines exactly when proprietary media is allowed, and what kind of approvals are needed to include them in the mix.

Demand campaign-level transparency. If it’s proprietary, it needs to be its own line item, have its own reporting, and its own performance metrics. Do not accept "bundled" reporting that hides the markup. Put a hard cap on what percentage of your total budget can go into proprietary solutions and only deviate from that cap with approval in advance.

And most importantly: Update your contracts to ensure you have the right to see the data. If the agency says, "you can't audit this because it's proprietary," that’s a red flag you need to discuss.

Proprietary media is a reality in 2026. You can use it to find value, or it can be used to extract value from you. The difference is entirely in your governance.