For a few years, retail media budgets grew on momentum. Spend was small enough that a ROAS number from each network, pasted into a planning deck, was enough to get the next increase approved.
That's over at most large brands. Retail media is now a line finance looks at closely, and the people reviewing it have started asking the questions they ask of every other investment. What would happen if we spent less? What does the next million get us? How do you know?
Platform ROAS doesn't hold up to those questions, and the teams that keep bringing it into the room tend to lose budget to channels with a better story. Polishing the slide won't help. What helps is a different set of numbers underneath it.
Why the usual deck fails
The standard retail media review adds up what each network reports. Amazon says this, Walmart Connect says that, Instacart and Target add their numbers, and the total gets divided by total spend. It looks rigorous. Finance will take it apart in about ten minutes.
Start with double counting. A shopper who saw your ad on two networks and bought on one can show up in both reports. Each network grades its own homework, with its own attribution window and its own rules, so the sum of their claims can easily exceed the sales you actually made from media.
Then there's organic demand. Attributed sales include shoppers who were going to buy anyway, especially on branded search and sponsored listings for products that already rank well. Finance knows your brand sold before retail media existed. When the deck implies most of today's sales came from ads, the whole thing loses credibility.
And none of it is comparable to anything else. Execs are weighing retail media against TV, trade spend, promotions and price investment. A platform ROAS built on a two-week click window can't sit next to any of those, so it ends up discounted or ignored.
What finance actually wants to see
Finance thinks in counterfactuals. Every investment gets judged on what changes because of it, so the core of the case has to be incremental sales: what you sold beyond what you would have sold without the spend, broken out by retailer and by tactic.
Then turn that into profit. A dollar of incremental revenue on a deeply promoted, low-margin SKU is worth a lot less than a dollar on a full-price hero item, and finance will do that math whether you do it or not. Put incremental gross profit next to incremental revenue and calculate iROI on both.
The piece most decks skip entirely is the next dollar. An average iROI tells finance how last year's spend performed, but the budget decision is about the increment, the next 10% or 20%, and returns usually fall as spend rises. Show where each retailer and tactic starts to flatten and you're answering the question finance is actually deciding on. It also makes the ask more believable, because you're showing where you'd stop spending.
Count the halo, but keep it in its own line
Retail media doesn't stay inside the retailer you bought it on. An ad on one network drives purchases on another. Display and offsite media drive shoppers into stores. Our cross-retailer halo research found roughly half of offsite media's total impact goes uncounted by standard reporting, and in some categories display drove more than 40% lift in-store.
Leaving that out of the business case undersells the channel badly, especially upper-funnel media, where we found ROI understated by 3 to 5x. But folding it straight into the headline number is how you lose the room. Halo is the part of the case finance will push on hardest, and if it's blended in, they'll discount everything.
So show it separately. Give finance the direct incremental return on its own, then the halo on top of it, then the total. The direct number is your floor, the one you'd defend under any scrutiny. The halo is upside with its own evidence attached. A CFO can accept the floor and argue about the rest, and that's a much better position than having the whole figure rejected.
A business case template
Here's the structure we'd put in front of a finance team, in the order they'll read it. Build it by retailer first, then roll it up.
| Line | What it shows | Why finance cares |
|---|---|---|
| Spend | Retail media spend by retailer and tactic | The investment being judged |
| Attributed sales | What each network reports | Reference only, so nobody thinks you’re hiding it |
| Incremental sales | Sales that wouldn’t have happened without the spend | The core of the case |
| Incremental gross profit | Incremental sales at actual margin, after promo depth | What the business actually keeps |
| iROI (revenue and profit) | Incremental sales and profit per dollar of spend | Comparable to TV, trade, promotions |
| Halo | Cross-retailer and in-store incremental sales, shown separately | Upside with its own evidence |
| Total incremental return | Direct plus halo | The full picture, after the floor is accepted |
| Return on the next dollar | Expected iROI on the next 10-20% of spend, by retailer and tactic | The decision actually on the table |
| The ask | Proposed spend change and expected incremental profit | What you want, and where you’d stop |
Keep attributed sales in the table even though you're not leaning on it. Finance has seen those numbers before. If they disappear, someone will ask why, and you'd rather the table answer that question for you: here's what the platforms claim, here's what actually moved.
What finance will push back on
"Who measured this?" Expect this one first. If the answer is the networks selling you the media, you're back where you started. An independent, third-party read that sees every retailer at once is much easier to defend than a stack of self-reported numbers.
"Wouldn't we have sold this anyway, with the promotion running?" Fair question, and the reason the baseline matters. Be ready to show that price changes, promotions, seasonality and distribution are accounted for before any lift is credited to media. If you can't show that, finance is right to be skeptical.
"Why is this lower than last year's number?" Because last year's number was attributed sales, and it was too high. Say so directly. Owning the correction buys more credibility than anything else in the deck, and it makes the new number far harder to dismiss.
"What happens if we cut it 20% instead?" The next-dollar analysis answers this in both directions. Show what you'd lose at lower spend, not just what you'd gain at higher, and the conversation moves from whether to fund retail media to how much.
"How sure are you?" Give a range. A precise point estimate invites an argument. A range with an honest floor reads like someone who knows the limits of their data, which is exactly who finance wants to fund.
Build the case on numbers that hold up
Incremental is the causal intelligence layer for commerce media. We give brands and agencies incremental sales and iROI across retailers, online and in-store, plus the halo most reporting misses, so the business case starts from numbers finance can test. Talk to us before your next planning cycle, or read the cross-retailer halo report for the research behind the halo figures.
