Marketing efficiency ratio — total revenue divided by total marketing spend. The blended, attribution-free view of whether your marketing pays.
MER (also called blended ROAS) takes all revenue in a period and divides it by all marketing spend in the same period — every ad platform, agency, influencer, and tool. Because it doesn't depend on attribution, it can't be inflated by two platforms claiming the same sale.
Your store did $180,000 in revenue last month and spent $45,000 on marketing across all channels. MER = 180,000 ÷ 45,000 = 4.0×, meaning marketing spend was 25% of revenue.
ROAS credits a platform with the revenue it claims to have driven, which is useful for comparing campaigns but tends to over-count as tracking gets harder. MER ignores who gets the credit and asks the business question: for every dollar we spent on marketing, how much total revenue came in?
It has to clear your break-even MER, which is 1 ÷ gross margin — the same logic as break-even ROAS. At a 50% margin you need at least 2.0× just to cover product costs and marketing. Enter your margin above to see how far above break-even you are.
What does MER stand for? Marketing efficiency ratio — total revenue divided by total marketing spend for the same period.
Is MER the same as blended ROAS? Yes. Both divide total revenue by total marketing spend, regardless of which channel is credited.
Should MER include organic revenue? Yes — that is the point. MER measures total revenue against total spend, so organic and repeat sales are included. Track it over time rather than as a one-off number.
