MER (Marketing Efficiency Ratio)
Total revenue divided by total marketing spend — a blended metric that resists attribution gaming.
Marketing Efficiency Ratio (MER) is total revenue divided by total marketing spend across all channels. Unlike ROAS, MER is not channel-attributed — it captures the blended business impact of marketing investment.
Context
MER has become the preferred primary metric for growth teams because it's less gameable than attributed ROAS. Individual platforms can report inflated ROAS (Meta and Google often both claim credit for the same conversion); MER captures reality.
Use MER at the executive level for investment decisions. Use channel-specific attribution at the optimization level for tactical decisions within a channel.
A DTC brand with $500K monthly revenue and $100K total monthly marketing spend has an MER of 5.0x. If revenue grows to $750K while spend scales to $200K, MER drops to 3.75x — a sign of declining efficiency even though absolute revenue grew.
MER is a trending metric, not an absolute one. What matters is whether MER is stable or improving as spend scales. A declining MER with rising revenue means marketing is hitting diminishing returns.
Related terms
Services that apply this
More Paid Media terms
CAC Payback Window
The number of months until a new customer's contribution margin equals the cost to acquire them.
CPM (Cost per Mille)
Cost per 1,000 impressions — the core pricing unit for paid media.
CPC (Cost per Click)
The cost of a single click on a paid advertisement.
CPA (Cost per Action/Acquisition)
The average ad cost per conversion event — the core paid efficiency metric.