Plain definition
Customer lifetime value, or LTV, estimates the economic value expected from a customer over the whole relationship. It is not one universal formula. A company may calculate it from revenue, gross profit, contribution after serving costs, or discounted cash contribution, but each version answers a different question. Customer acquisition cost, or CAC, is the sales and marketing spend needed to win a new customer on a stated basis.
The distinction matters most when LTV is compared with acquisition cost. Revenue LTV can be large even when delivery, support, payment fees, or onboarding consume most of that revenue. A profit- or contribution-based LTV is usually more useful for deciding how much acquisition spending the business can recover.
Illustrative example
Monetary examples use Saudi riyals (SAR). The same principles apply in other currencies.
Suppose a subscriber is expected to pay a month for 12 months. Revenue LTV is . If direct service, payment, and support costs total a month, contribution after those direct costs is a month and contribution LTV is .
The company pays to acquire the subscriber. Calling the “return” would hide the economics: the relevant comparison is against the stated contribution basis, and the business still needs the monthly contribution to arrive before it can recover CAC.
| Monthly contribution after direct costs | |
|---|---|
| Expected months | |
| Contribution LTV |
A lifetime estimate is especially uncertain when the company has little retention history. It should be updated from observed customer behavior rather than treated as a permanent fact.
Why it matters
LTV prevents a growth plan from looking healthy merely because customers generate high revenue. It forces the team to ask which costs follow the customer, how long customers actually stay, and whether the cash from the relationship arrives soon enough to fund acquisition.
Practical consequence
Publish the formula beside the result: customer population, retention assumption, revenue or profit basis, variable costs, period, and any discounting. Calculate it by comparable customer group or product where behavior differs. Review the estimate against realized retention and contribution after the same direct costs, and lower it when the evidence does not support the assumed lifetime. Do not use an industry target as a substitute for those inputs.