Break-Even ROAS vs MER

Break-Even ROAS

The ROAS at which gross profit exactly covers ad spend, calculated as one divided by your gross margin expressed as a decimal.

It converts margin into a minimum acceptable return, so a forty percent margin needs two and a half times just to break even. Anything below that loses money however good the platform's number looks. Two errors recur: using net rather than gross margin, and forgetting that returns, discounts, and shipping subsidies quietly lower the margin the calculation depends on.

MER

Total company revenue divided by total marketing spend across all channels, a blended efficiency ratio rather than any per-campaign measurement.

It sidesteps attribution entirely by refusing to assign credit, asking only what every marketing dollar coincided with in revenue. That makes it stable when tracking degrades, but blunt: it also moves with organic demand, email, retention, and seasonality. The common misreading is diagnosing a single channel from it, which by construction it cannot tell you anything about.

Use Break-Even ROAS when

• You're setting a Target ROAS floor for a specific campaign or channel and need the exact minimum your margin allows.
• You want a number granular enough to apply per campaign, per channel, or per product line.
• Your margin just changed and you need to recompute the bar before judging anything against it.
• You're building a dashboard where individual channels need their own pass or fail line, not just a company-wide one.

Use MER when

• You want one number that captures whether the entire marketing budget, blended across every channel, is worth what it costs.
• Attribution across your channels feels unreliable and you want a metric immune to that specific problem.
• You're reporting to ownership or finance who think in total spend versus total revenue, not campaign-level detail.
• You want to hold the whole marketing budget against your break-even ROAS as a single sanity check, even knowing it can't tell you which channel to fix.