Blended vs. per-channel CAC: which one to trust when

Blended CAC is the honest north star; per-channel CAC guides where to spend but is polluted by attribution. Knowing when each one lies keeps you from over-crediting a channel and starving the business.

Blended CAC (all spend divided by all new customers) can't be gamed and tells you if the whole business is acquiring efficiently. Per-channel CAC is essential for allocation but is distorted by attribution: every channel claims the same sale. AI computes both from your numbers and flags when the per-channel view misleads you.

Blended CAC and per-channel CAC answer different questions. Trust the wrong one and you over-fund a channel that was just taking credit for organic sales.

AI can compute both from your spend and new-customer counts. You supply the real numbers, because it must never invent spend, conversions, or a channel's attributed sales.

What you'll learn

Compute blended CAC first, and treat it as the truth
Compute per-channel CAC for allocation, not for scoring
Watch for attribution pollution
Build a simple reconciliation habit