Marketing & Advertisingadvanced
Marginal CAC
Definition
The cost to acquire the next customer as you scale spending, which usually rises because the cheapest, easiest customers are reached first.
Why it matters
Marginal CAC warns you when adding more ad spend stops being worth it, even while your average CAC still looks healthy.
Example
Your average CAC is £30, but pushing budget higher costs £60 for each extra customer, so your marginal CAC is £60.
Related terms
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