Your ROAS Is Lying to You: Why Platform Numbers and Bank Deposits Disagree

Meta says 4x, Google says 6x, and the bank account says something else entirely. Here's why attributed ROAS overstates reality and which number should actually drive your budget.

What is the difference between ROAS and MER?

ROAS as reported by an ad platform is revenue that platform claims, divided by spend on that platform. MER, or Marketing Efficiency Ratio, is total business revenue divided by total advertising spend across all channels. MER can't be inflated by attribution because both figures come from your own records.

Why is my Meta ROAS higher than my actual revenue growth?

Because platforms report attributed revenue, not incremental revenue. Multiple platforms can each claim the same sale, and retargeting campaigns take credit for purchases that would have happened anyway. The sum of platform-reported revenue routinely exceeds real revenue.

What is a good blended ROAS?

It depends entirely on gross margin. At 60 percent margin, break-even sits near 1.67. At 30 percent margin you need roughly 3.3 just to cover product cost. There's no universal benchmark, only your own break-even and whether you're above it.

Should I use platform ROAS at all?

Yes, but only for decisions inside that platform, such as which campaign or creative to scale. Use blended ROAS for decisions about total budget and channel mix.

How do I measure incremental ROAS?

Through holdout testing. Switch a channel off in one geographic region while leaving it on elsewhere, then compare total revenue between the two. It's the most practical incrementality test available to most businesses.