Why iROAS Is the Metric That Matters Standard for Grocery CMOs

For today’s grocery CMOs, the mandate is clear: marketing investments must translate into measurable business results. Boards demand hard proof of ROI. CPG partners expect accountability that justifies their budgets. And shoppers demand personalized engagement that builds loyalty and growth.

The role of the CMO has never been more critical to the bottom line – but the key question remains: are we proving real growth, or just reporting statistics?

The Problem With ROAS

For years, Return on Ad Spend (ROAS) has been the default metric for measuring marketing effectiveness. It’s simple: revenue attributed to advertising divided by ad spend.

But here’s the flaw: ROAS counts all sales tied to an ad campaign, including those that would have happened anyway. This inflates results, creating a false sense of impact. For grocery CMOs, the risk is clear — numbers that look good on paper but don’t reflect true business growth.

The Power of iROAS

Incremental Return on Ad Spend (iROAS) changes the equation. Instead of counting every attributed sale, iROAS isolates incremental lift — the new sales, trips, and baskets that only occurred because of the campaign.

For grocery CMOs, this distinction is game-changing:

• Protect margins by cutting wasted spend and proving profitable growth.
• Defend budgets with board-ready evidence of true marketing impact.
• Strengthen long-term growth by showing that campaigns create incremental shopper value, rather than just subsidizing existing purchases.

The takeaway is simple: iROAS elevates retail media from vanity metrics to a driver of sustainable, defensible growth.

How to Get There

Knowing that iROAS is the gold standard is one thing — achieving it is another. Too often, grocery CMOs are stuck with fragmented data, legacy systems, and reports that stop at surface-level attribution. To prove incrementality, you need the right measurement foundation and the right partner. That means:

• Loyalty and Point-Of-Sale (POS) data
  Incrementality lives in the details of shopper transactions. Loyalty and POS data are the keys to unlocking this view, capturing who bought what, when, and how behavior changed after a campaign. For CMOs, this is the difference between reporting “a sale happened” and proving “this campaign drove a new trip, a bigger basket, or a lapsed shopper’s return.”

• Closed-loop reporting
  Most attribution today stops at clicks and impressions. Closed-loop reporting connects campaigns directly to actual purchases, tying ad exposure to shopper transactions. This is essential for proving whether sales were incremental versus inevitable. Without closed-loop measurement, CMOs risk relying on inflated ROAS numbers that don’t reflect true shopper behavior.

• Advanced analytics
  Incremental measurement can’t just be backward-looking. CMOs need real-time insights that surface campaign performance while it’s still in flight, enabling teams to optimize budgets on the fly. Advanced analytics tools reveal patterns across shopper segments, categories, and campaigns, helping marketing teams refine investments and consistently demonstrate iROAS.

• IAB-aligned standards
  Incrementality only matters if it can be measured consistently across campaigns and channels. That’s why the Interactive Advertising Bureau (IAB) has become the gold standard for retail media measurement. IAB standards create a common framework for defining audiences, measuring outcomes, and validating results — benchmarks that boards, investors, and CPG partners already recognize and trust. For grocery CMOs, aligning iROAS to IAB ensures results aren’t just isolated wins but credible, apples-to-apples metrics that can be compared across the entire media mix. This level of consistency is critical for proving true incrementality and defending marketing investments at the highest levels.

This is where Swiftly delivers unique value. Purpose-built for grocery, Swiftly’s platform connects to retailer data sources, applies user-level insights, and provides transparent, IAB-aligned reporting. The result: a clear, measurable view of incrementality that CMOs can take to the boardroom with confidence.

The Bottom Line

The future of grocery retail media will be defined by transparency and accountability. Boards and CPG partners will no longer settle for inflated ROAS metrics — they’ll demand proof of real growth.

For grocery CMOs, iROAS is the new standard for proving that marketing spend drives profitable, measurable business results. And with Swiftly, you’ll have the tools and insights to defend budgets, demonstrate impact, and lead your organization into a future defined by growth.

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