Marketing / Finance
Marketing Efficiency Ratio MER (aka "blended efficiency ratio"; aMER = acquisition MER)
Total revenue divided by total marketing spend, a deliberately blended, attribution-free read on whether the whole marketing engine pays for itself.
The fork, why two teams get different numbers
MER and blended ROAS share a formula (revenue / spend) but MER usually means TOTAL marketing spend while ROAS means ad spend only, first fork.
In the Metric Library
- The full fork, both definitions worked all the way through
- The trap that makes the number lie, on a real export
- Every formula variant, spelled out
- The reconciliation anchor, what to tie it to and when to refuse
Reference: DTC/ecommerce unit-economics convention · GAAP/ASC (revenue recognition · reference)