The return on each Euro/Dollar invested in marketing — measured on new customer revenue only.
Formula
Acquisition Marketing Efficiency Ratio (aMER) = New Customer Revenue / Marketing Costs
Explanation
How much new customer revenue you generate for each Euro/Dollar invested in marketing. Unlike MER — which looks at all revenue — aMER focuses exclusively on the revenue from customers placing their first order. This makes it a direct measure of how efficiently your marketing is acquiring new customers.
Use aMER alongside MER to understand how much of your marketing return comes from acquisition vs. returning customers.
Notes
New Customer Revenue = Net Revenue from customers placing their first order only.