An alternative ad-efficiency metric to ACOS: expresses ad performance as a return ratio (revenue generated per dollar of ad spend) rather than ACOS's cost ratio (spend as a percentage of revenue). The two are inverses of the same underlying numbers.
For sellers who prefer thinking in ROAS terms, the same per-keyword triage applies in reverse: flag or remove any keyword whose ROAS falls at or below the break-even ROAS threshold for the product's margin, mirroring the ACOS-above-margin removal rule used in the Excel-Based PPC Report Color-Coding Workflow.
Some sellers track ROAS instead of ACoS as their primary profitability lens — the two are inverses of each other (ROAS = revenue/spend vs. ACoS = spend/revenue). Practically, this means comparing ROAS against a break-even ROAS threshold, the mirror of comparing ACoS against your profit margin in the Leading Actions vs. Lagging Metrics (PPC Diagnosis Framework) diagnostic funnel — same decision, different-shaped number.