# MER (marketing efficiency ratio)

> MER is total revenue divided by total marketing spend across every channel, also called blended ROAS.

Canonical: https://use-addy.site/glossary/mer
Last updated: 2026-10-26

Also called: blended ROAS

**Formula:** MER = total revenue ÷ total marketing spend

Platform ROAS relies on each platform's own attribution, and platforms often credit themselves for the same sale. MER sidesteps that by looking at the whole business, which makes it a steadier number for deciding overall budget.

## Related

- [ROAS (return on ad spend)](https://use-addy.site/glossary/roas)
- [CPA (cost per acquisition)](https://use-addy.site/glossary/cpa)