Glossary · Measurement
What is MER?
Marketing Efficiency Ratio
Quick Answer
MER (Marketing Efficiency Ratio) is total revenue divided by total advertising spend across every channel — not just the revenue platforms claim credit for. Because it uses your real top-line and your real ad bill, MER cannot be inflated by attribution overlap, which makes it the number most operators check first.
In Detail
Understanding MER
Platform-reported ROAS is calculated inside each platform's own attribution model. Meta counts a sale it influenced, Google counts the same sale, Amazon counts it again — so summing platform ROAS across channels reliably overstates performance. MER sidesteps the whole problem: one revenue figure from your books, one spend figure from your invoices.
The trade-off is that MER is blunt. It will not tell you which channel to cut, and it moves with seasonality, organic strength and price changes as much as with media performance. It is a health check, not a diagnostic.
Business Impact
Why MER Matters
MER is the number that survives a board meeting. When channel dashboards disagree, MER is the version of the truth your P&L recognises.
It is also the earliest warning of over-attribution: if platform ROAS is rising while MER is flat, you are not growing — the platforms are simply claiming more credit for the same sales.
From Our Own Book
How ATIL Works With MER
Our Amazon book gives a concrete illustration: ₹10.32 Cr of ad spend against ₹146.09 Cr of total marketplace revenue across 51 brands — an MER of roughly 14×, while the ad-attributed portion alone is ₹55.19 Cr (a 5.35× blended ROAS).
The gap between those two figures is the point. Roughly 62% of the revenue in our portfolio is not ad-attributed — it is organic sales that advertising helped build. An account judged only on the 5.35× would be systematically undervalued.
Figures are drawn from ATIL's managed portfolio and measured through platform APIs, not estimated.
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