Blended CAC is your total customer acquisition cost across every channel combined, including organic and referral, divided by all new customers. It differs from paid CAC, which counts only customers won through paid channels. Blended CAC is lower because it includes customers who cost nothing to acquire.

Blended CAC is the honest number and the misleading one at the same time. It is honest because it reflects your real average cost. It is misleading because referral and organic customers hide how expensive your paid channels actually are. If you plan to scale paid spend, look at paid CAC, not blended.

Example:

You win 20 customers: 12 from referral (free) and 8 from $40,000 of paid spend. Blended CAC is $40,000 / 20 = $2,000. Paid CAC is $40,000 / 8 = $5,000: same business, very different stories.

Should I use blended or paid CAC?

Use blended CAC to understand current efficiency. Use paid CAC to forecast what scaling will cost, because new growth usually comes from paid channels, not more referrals.

Why is blended CAC lower than paid CAC?

 
Blended CAC includes customers acquired through free channels like referral and organic, which pulls the average down.