In practice
Platform cost per acquisition is not CAC. Real CAC adds agency fees, tooling and the sales time it took to close, which is usually where the number stops flattering the channel.
We calculate it per segment: the CAC that works for enterprise rarely works for self-serve.
Why it matters
It is the number finance recognises. A channel that cannot show its CAC will lose budget to one that can, regardless of how good its engagement looks.
Related terms