CPG · Answer

Does better measurement win retail media budget?

Not so far — and the reason is that nobody has tried it yet. Spend is moving the other way. Of roughly $10.53bn in net-new US retail media spend forecast for 2026, $9.42bn, over 89%, goes to Amazon and Walmart, and neither holds an accredited metric for attributed sales, ROAS or incrementality. Meanwhile the network furthest along on measurement — Kroger, in MRC pre-audit since June 2026 — is alone there, and nothing has been granted. That looks like proof that measurement does not sell, and it is not. No network has yet put an audited sales number in front of buyers, so the thing being argued for has never been offered. The null is on the market, not on the idea. What the evidence does show is why the move is hard: most of the money does not come from the budget that would reward it.

The evidence

The spend is concentrating on the networks with nothing audited.

Of roughly $10.53bn in net-new US retail media spend forecast for 2026, $9.42bn — over 89% — goes to Amazon and Walmart, with every other tracked network expected to divide the remainder. Attributed sales, ROAS and incrementality are accredited at zero networks, those two included.

The one network that submitted its sales numbers is on its own.

Kroger Precision Marketing put attributed sales, incremental sales, aROAS and iROAS into MRC pre-audit, in process since June 2026. Nothing has been granted, and no other network has submitted the same metrics. There is no second data point to compare it against.

The treatment has never been shipped, so the experiment has not run.

Measuring whether audited sales reporting moves budget requires a network that publishes audited sales reporting. None does. A market that has not been offered something cannot be said to have declined it.

Most retail media money starts in a budget that does not reward incrementality.

62% of retail media dollars still originate in trade and shopper budgets rather than brand marketing, even though brand marketing holds the plan in 71% of organizations. Joint business plans are recorded crediting $1,000 of self-serve spend as $750. A dollar negotiated as trade is not evaluated on incremental sales, whoever measures it.

The incrementality numbers that do exist are not comparable either.

Albertsons Media Collective research published in March 2026 found that iROAS can vary 6.5x and flips the result in 83% of campaigns depending on filtering, matching and revenue-calculation choices — choices the network makes rather than the buyer.

What would have to be true for this to be wrong

Kroger is the live test. If its pre-audit completes and its share of net-new spend moves against the concentration trend over the following year, audited sales reporting has been shown to move budget and this answer is wrong. If the audit completes and share does not move, the idea has been tested and failed on its merits rather than on its absence. Either outcome is more informative than today's, which is that nobody has run it.

Share figures eMarketer, January 2026. MRC digital accreditation directory and services-under-review listing, checked September 2026. Kroger pre-audit status from the MRC services-under-review listing. Budget-origin figures Forrester, published January 2025, and Dentsu, 2025 (n=100, fielded August 2024). Albertsons iROAS variance research, March 2026, published by Albertsons Media Collective. Desk review, 22 sources, no instrument run.
Every row behind this answer is published in the standing study at cultmath.com/research/marketing/open-loop-retail-media, which is re-run on a schedule and corrected in place, dated.
Published 2026-11-09 by Ipalibo Da-Wariboko, CULT+MATH LLC. Where a number could not be sourced, this page says so and gives none.

This is one of six decisions covered in the cpg decision brief — each with the evidence behind it, who owns it, who it is contested with, and what would have to be true for the answer to flip.

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