Payback period

Divide your customer acquisition cost by the monthly profit from one customer. If CAC is $300 and a customer brings $50 a month after costs, payback is 6 months. Until then, that customer has cost you money.

With little cash, a short payback period matters more than a high lifetime value. Ads with a 12-month payback can empty a small bank account. Channels like warm outreach cost mostly time, not cash. Calculate CAC and payback period before you raise an ad budget.