Marketing Efficiency Ratio (MER) compares total revenue with total marketing spend. It is an aggregate metric for evaluating acquisition efficiency without relying on the attribution model of a single platform.
How it works
It is calculated by dividing total revenue for a period by the defined marketing spend. Unlike platform ROAS, it does not attempt to assign every sale to a specific ad and can provide a more management-oriented view.
Practical example
With $500,000 in revenue and $100,000 in marketing spend, MER is 5. If platform ROAS improves while MER declines, attribution inflation or an unfavorable mix shift may be involved.
Why it matters
It is useful for budgeting, forecasting and cross-channel analysis, especially when multiple touchpoints contribute to conversion and platforms claim overlapping revenue.
What to watch
MER does not replace channel-level analysis: because it is aggregated, it can hide local inefficiencies. It should be used with margin and incremental growth.