The retail media story for the last four years has been a growth story. Total ad spend through retail media networks moved from a niche line item into a mainstream channel that, by most analyst counts, has now passed linear TV in the U.S. The pitch was clean: closed-loop attribution, first-party data, and measurable ROAS in a world where the rest of digital advertising was getting harder to measure.

That pitch is now under audit. And the audit isn't going well for everyone.

We spent the spring talking to brand-side media leads, agency planners, and a handful of RMN operators. The conversation has shifted noticeably over the last six months. Brands aren't pulling out of retail media — the channel is still growing in aggregate — but the way budgets are being allocated within the channel is being repriced. The networks that can survive an honest attribution conversation are taking share. The networks that can't are about to have a difficult second half.

What "honest attribution" means in 2025

The version of attribution that retail media networks have been selling is, in most cases, last-touch within the retailer's walled garden. A shopper sees a sponsored product ad on the retailer's site, buys the product (or anything from the brand) within some attribution window, and the sale gets credited to the ad.

That model worked when the alternative was Google or Meta attribution that was getting noisier by the quarter. It works less well when brand-side analytics teams start running their own incrementality tests.

A senior media director at a CPG brand we spoke to summarized the shift: "We ran holdout tests on three of the top RMNs last year. On one of them, we couldn't find incrementality at all. On another, the incremental ROAS was less than a third of what the network reported. We're still spending with all three. We're just no longer treating the reported numbers as real."

That's the credibility crisis in one quote. The number on the dashboard is not the number the finance team trusts.

The split between the top tier and everyone else

The top two or three RMNs — the ones with enough scale to be unavoidable, and enough technical sophistication to support real measurement — are not where the pressure is landing. Brands need to spend there. The measurement debate is happening, but the budget commitment continues.

The pressure is landing on the mid-tier. Networks that built their pitch on closed-loop attribution but don't have the data infrastructure or scale to survive a third-party measurement audit are seeing budget conversations that were not on their 2025 deck.

Several agency planners told us they've started classifying RMNs into a tier system internally: those that pass incrementality tests, those that fail them, and those that won't run them. The third bucket is the one with the worst 2025 forecast. A senior planner at a top-five agency told us: "If a network won't participate in a clean incrementality study at this point, we're treating that as the answer."

What brands are demanding, and what they're getting

The asks from the brand side are increasingly consistent:

• Clean room access or equivalent, so brand-side analytics can rerun attribution on their own.
• Holdout testing as a standard, not as a custom one-off that takes six months to negotiate.
• Transparency on what counts as a "view" and what counts as a "click" — definitions vary across networks in ways that aren't always disclosed.
• Distinction between in-store sales lift and online sales lift, especially for brands where the channel mix matters to category management.

What brands are getting is partial. The top RMNs are moving on clean rooms and standardized measurement, in part because they can afford the infrastructure investment and in part because they know the alternative is losing share. The mid-tier is moving slower, and in some cases not at all.

What to watch in H2 2025

The interesting question isn't whether retail media keeps growing in aggregate. It will. The interesting questions are which networks lose share, which ones consolidate, and how quickly the standards conversation — which has been mostly an IAB-and-MRC affair so far — produces something with real enforcement teeth.

A few signals worth tracking: how 2026 upfront commitments shake out, whether any mid-tier RMN gets acquired or quietly wound down in the back half, and whether the larger holding companies start publishing their own incrementality benchmarks publicly. If that last one happens, the credibility conversation moves from private decks to public scoreboards, and the repricing accelerates.

The growth story for retail media isn't over. The "trust the dashboard" story is.