Marketing & Sales
Observation 003
· 2 min read
The cheapest acquisition is not automatically the best acquisition.
Optimizing for cost per acquisition finds the customers who are cheapest to reach, not the ones worth reaching.
One number
−8.2%
illustrative fall in CAC, bought with weaker customers
One mechanism
Platforms optimize toward the conversion you ask for. Ask for cheap conversions and you get customers who convert easily and return rarely.
One decision
Set acquisition targets on 90-day contribution per customer, and let CAC rise where the cohort earns it.
Illustrative. CAC falls 8.2% and the channel team reports efficiency. Ninety days later, the cohort acquired at the lower cost is worth 14.6% less than the one before it.
Nothing on the acquisition dashboard is wrong. The platform did exactly what it was asked: find conversions at a lower price. It found customers who convert easily and return rarely.
The fix is a different target. Judge acquisition on what the customer is worth at 90 days, after variable costs, and let CAC rise where the cohort earns it.
Evidence · Illustrative · Not client data