Retail media's CTV push is creating a measurement blind spot

A tollbooth is excellent at one thing: it counts every car that passes through, logs the exact time, and knows precisely how many vehicles came from that direction. What it can't tell you is where any of those cars started their trip, or where they're actually headed once they clear the gate. It only sees the moment a car is inside its lane.

Retail media networks are running into a version of that same limitation right now, and it's arriving at an inconvenient time. These platforms are pushing hard into premium CTV inventory, expanding well beyond the lower-funnel placements they built their reputations on. That expansion means more budget is flowing through systems that were only ever built to see what happens inside their own lane, and brands need to understand exactly how much that limits what they can actually learn from the spend.

Key takeaways

• Retail and commerce media networks have the lowest buyer confidence of any CTV buying method, according to recent IAB data.
• These same networks are actively expanding into premium CTV inventory, well past their original lower-funnel placements.
• Retail media measurement is closed-loop by design, built to report on activity that happens inside the platform.
• A CTV impression served through a retail media network often drives action somewhere else entirely, and that activity is invisible to the platform that served the ad.
• As more budget shifts into retail media CTV, the share of impact sitting outside any single platform's reporting grows right along with it.
• Closing this gap requires measurement that can see across retail platforms and connect spillover back to the campaign that caused it.
• Brand safety and trust concerns get most of the attention, but the bigger long-term risk is a growing measurement blind spot brands aren't yet accounting for.

Retail media's CTV expansion, and where trust is thinnest

IAB data on CTV buyer confidence found that retail and commerce media networks fared worse than any other buying method, with 59% of advertisers reporting little or no confidence in the inventory. That's a striking number on its own, but it's worth pairing with the other half of the story: these are also the networks pushing hardest into premium video right now, expanding their footprint well past the retargeting and sponsored placements they were originally known for.

Most of the trust conversation around that stat has focused on inventory quality, brand safety, and placement transparency. Those are real concerns, but there's a second problem sitting underneath the trust gap that gets a lot less attention, and it doesn't go away even if every placement is perfectly verified.

Walled gardens report what happens inside their walls

Retail media measurement is closed-loop by design. A retail platform can tell you, in detail, what happened once someone interacted with an ad on its own site or app: 

• what they clicked
• what they added to a cart
• what they eventually bought

Marketers want data on these interactions. Of course. But even this has a baked in limitation: someone that doesn’t click immediately may still purchase later, and if they do it off of the site or app, that conversion won’t be in the reporting. That's simply the boundary of what these platforms were built to see.

CTV compounds this problem because a CTV impression doesn't work the same way a sponsored product placement does. Someone watching a streaming show doesn't pause to shop on their phone. They keep watching, and whatever action that ad eventually drives, if it drives one at all, usually happens somewhere else, sometimes days later. A closed-loop reporting system has no way to follow that path once it leaves the platform.

CTV's real value usually shows up somewhere else

This is where the blind spot actually costs brands something. A CTV ad served through a retail media network might not drive an on-platform purchase at all. It might drive a branded search a day later, a direct visit to the brand's own site, or a purchase completed through an entirely different retailer. All of that is real, attributable impact from the campaign, but none of it shows up in the reporting from the platform that served the ad because it can only report on what happens inside its own walls.

For CTV specifically, where delayed and indirect impact is often the majority of the value, it means a huge share of what the campaign is actually doing goes uncounted by the very system a brand is relying on to judge whether the spend is working. Because of this, CTV gets cut more often than it should.

The blind spot gets bigger as the budget does

There's a scaling problem hiding inside this.

Every dollar that shifts from lower-funnel retail placements into premium CTV increases the share of total campaign impact that's happening off-platform. A brand that judges CTV performance purely on what one retail media dashboard reports is working with a smaller and smaller slice of the real picture as that budget grows, right at the moment when getting an accurate read matters most.

What closing the gap actually requires

Closing this gap means measuring impact across retail platforms instead of trusting any single network's self-reported numbers on their own. That means connecting activity across the retailers where a brand actually sells, tracking daily so it can keep pace with fast-moving CTV spend, and tying spillover revenue back to the specific campaign that caused it rather than letting it disappear into an unattributed bucket.

Without that connective layer, brands are left comparing performance across retail media networks using numbers that were never designed to be compared to each other, and with only part of the performance represented.

Where Prescient comes in

Prescient's marketing mix model measures campaign impact across your full omnichannel footprint, including retail marketplaces like Amazon, Walmart, Target, Ulta, and others where your brand sells. Our models update daily and tie spillover revenue, the branded searches, direct visits, and off-platform purchases a CTV impression drives, back to the campaign that caused it, instead of leaving that value trapped in whichever platform happened to serve the ad.

That gives you a consistent way to judge CTV performance across every retail media network you use, rather than piecing together conclusions from reporting that was only ever built to see one lane at a time. We can use the direct data from the retail media networks driving this CTV push, including Roundel, Amazon Ads and Amazon DSP, and Walmart Connect, alongside the retail revenue data from the retailers where those campaigns actually convert. That means a CTV placement running through Roundel can be measured against what it drives at Target, at another retailer entirely, or back on your own site, instead of stopping at whatever Roundel's own dashboard reports.

If you want a clearer picture of what your retail media CTV spend is actually driving, book a demo and see how Prescient can connects the dots across your retail footprint.