What is MER?

Marketing Efficiency Ratio

DEFINITION

Marketing Efficiency Ratio (MER) is total revenue divided by total marketing spend across all channels. A blended view, not single-channel.

FORMULA

MER = Total revenue ÷ Total marketing spend

BENCHMARKS

Healthy DTC brand: 3-5x · Scaling: 2-3x · Mature/profitable: 5-8x

DEFINITION

MER: Marketing Efficiency Ratio (MER) is total revenue divided by total marketing spend across all channels. A blended view, not single-channel.

Why MER matters

MER cuts through attribution confusion. It does not care which channel gets credit — just the bottom line. Best measured at the business level, month over month. Google Ads might report 6x ROAS, Meta 3x, but MER might be 2.5x due to overlap.

Worked example

Plug a real number into the formula to see MER in action:

// Formula

MER = Total revenue ÷ Total marketing spend

// Example calculation

$200,000 revenue ÷ $50,000 total spend = 4.0× MER

Numbers are illustrative. Try our Customer LTV Calculator for your real numbers.

Common mistakes with MER

1
Looking at single-channel ROAS in isolation instead of blended MER. Last-click attribution overweights bottom-funnel channels and starves top-of-funnel.
2
Setting a uniform target across products with different margins. A 2× ROAS is profitable on 80% margin and unprofitable on 20%.
3
Optimizing CAC without measuring LTV. Cheap customers with bad retention destroy unit economics.

How to improve MER

Run incrementality tests every quarter to validate which channels actually drive new revenue vs steal credit.
Build a unit economics dashboard separating CAC, LTV, contribution margin, and payback by channel and cohort.
Establish a contribution margin floor for each channel — pause spend when margin drops below threshold for 14 days.