CAC Payback Period

Biological Parallel

CAC Payback Period measures how quickly you recover the cost of acquiring a customer. In nature, this is the 'offspring investment payback': how long until a juvenile contributes more energy than it consumes. Salmon invest heavily in eggs and fry (high CAC), but they never recover the investment—semelparous species die after spawning. Elephants invest 22 months in gestation plus years of nursing, but calves eventually contribute to herd defense and knowledge transfer, achieving payback. Short payback periods enable iteration; long ones require certainty. If your CAC payback exceeds your cash runway, you're a salmon without enough river.