MER · Marketing Efficiency Ratio
Total revenue divided by total marketing spend over a given period.
Technical meaning
Unlike ROAS, MER does not try to attribute each sale to an ad; it measures whether the whole setup brings in more than it costs. It is the indicator Contrast favours for companies present on several channels, because it withstands the limits of attribution and signal loss.
Formula
MER = total revenue ÷ total marketing spend