ROAS is No Longer Enough

Retail media is growing fast, but many teams are still making budget decisions based on overly simplistic attribution signals, rather than true growth drivers. These five questions help commerce media leaders understand what is actually driving sales, compare performance more accurately across retailers, and invest with greater confidence. And be sure to download our full playbook for more!

Retail media needs a causal measurement standard

Retail media is now too important and too expensive to run on weak signals.

$53.7 billion in US retail media network ad revenues in 2024 (IAB) — up 23% year over year. That kind of growth raises the stakes for every team responsible for spend, performance and sales impact. The bigger commerce media gets, the more expensive bad decisions become.

Many of those decisions are still being made on last-touch ROAS. ROAS tells an incomplete story:

• Over-credits demand capture
• Makes comparison look cleaner than it is
• Ignores wider context like promotions, competition and seasonality
• Undervalues demand-building activity

ROAS might look persuasive when you're looking at campaigns in a bid management platform. In the world of media planning, though, it's a weak signal for linking spend to business outcomes or deciding where the budget should move next. Better measurement starts with better questions.

1. What sales were actually caused by this investment?

Why it matters

Last touch attribution can look convincing, especially in high-intent environments. But not every sale that followed the media was caused by it. Some would have happened anyway. Some were shaped by pricing, promotions, or other factors outside the campaign.

What it changes

It moves the conversation from what got credit to what created lift. That makes budget decisions sharper.

2. Which activity is creating growth, and which is just getting credit?

Why it matters

Not every campaign that looks efficient is actually driving growth. Some activity builds new demand, while other activity captures intent that already exists. Because demand conversion typically happens close to the point of sale, it is credited more often in a click-based attribution model. As a result, budgets can skew toward what performs best in-platform, rather than what is truly driving incremental sales.

What it changes

It moves beyond assigning full credit to the demand capture activity. Instead, it enables a more accurate view of how much impact each touchpoint has — so teams can invest more confidently in what is genuinely driving incremental growth.

3. How can performance be compared using a single, consistent framework across retailers and the full funnel?

Why it matters

Retail media rarely operates on a single standard. Platforms use different formats, definitions and measurement logic, which can make side-by-side performance look cleaner than it really is. A strong result in one environment is not always directly comparable to a strong result in another.

What it changes

It gives teams a more consistent way to compare performance across retailers. Planning, forecasting and budget decisions become much more fact-based.

4. Where should the next dollar go to drive the most incremental growth?

Why it matters

Measurement should go beyond explaining what happened and guide what to do next. Differences in incremental impact mean the marginal iROI on the next dollar spent can vary significantly, so investment decisions should follow the biggest growth levers.

What it changes

It turns measurement into an allocation tool. Budget can move toward the activity that is actually creating more growth, not just receiving more credit.

5. How much investment is needed to hit the growth goal with confidence?

Why it matters

Measurement should not stop at performance readouts. Leaders need a clearer basis for planning, forecasting and setting investment levels across retailers.

What it changes

It brings measurement into the planning stage. Instead of stopping at what happened, teams can plan against what it will take to hit the next growth target.

What this looks like in practice

These questions matter because they change how media owners allocate budget.

Incremental worked with a large brand on a three-week Amazon search pilot using always-on causal measurement. As the model retrained daily, spend moved toward the campaigns with more room to grow and away from those where returns had started to flatten.

Results

• 1,500+ budget decisions per day
• 3,000+ optimizations in three weeks
• +63% improvement in iROI
• $3.3M+ estimated annualized incremental revenue

That is the real test. Not whether measurement makes reporting sound smarter, but whether it changes where the money goes.

Why Incremental

Incremental is built for the decisions retail media teams actually have to make: what is driving sales, how performance compares across retailers and where budget should move next. It is purpose-built for commerce media, makes incrementality actionable day to day and remains media neutral when budget and performance decisions are on the line.