Customer Lifetime Value (LTV)
Customer Lifetime Value (LTV)
Customer lifetime value (LTV or CLV) estimates the value of a customer relationship over time. The value may be expressed as revenue, gross margin or profit, depending on the model, so the definition and assumptions must be stated.
In subscription businesses it is usually calculated from average revenue per account, gross margin and churn rate. Compared with customer acquisition cost, LTV shows whether winning customers is worth what it costs.
How Customer Lifetime Value Works
One simplified, undiscounted estimate for subscription products is:
Estimated gross-margin LTV = (Average revenue per account per period × Gross margin fraction) ÷ Customer churn rate for the same period
The logic is simple. If customers churn at a steady rate, the average customer lifetime is 1 divided by the churn rate: at 2% monthly churn, the average customer stays about 50 months. Multiply that lifetime by the margin each customer produces per month and you get LTV. Use matching time units, for example monthly revenue with monthly churn.
Three choices make LTV more honest:
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Name the value basis. Revenue LTV, gross-margin LTV and discounted contribution or net-profit LTV are different measures. The formula above estimates gross margin, not net profit: it does not automatically deduct every cost of serving the customer or account for the time value of money. State what costs and discounting your model includes before comparing estimates.
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Segment it. An average across small and large customers hides very different economics.
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Be careful with expansion and long horizons. The simple formula assumes constant churn and no expansion revenue. Do not substitute net revenue churn for customer churn: expansion can make the former zero or negative, producing a misleading result. A zero customer-churn estimate also makes this formula undefined; it does not prove infinite value. A cohort model over an explicit horizon is more useful when assumptions are unstable.
Why Customer Lifetime Value Matters
LTV informs acquisition decisions but is not a spending budget by itself. Compared with customer acquisition cost (CAC), it helps assess unit economics. Cash flow, payback time, uncertainty and the cost basis still matter; one LTV:CAC benchmark is not suitable for every business.
LTV also shows why retention is so powerful. Under the constant-churn approximation, small improvements in churn have a large effect: cutting monthly churn from 3% to 2% stretches the average lifetime from about 33 to 50 months, raising LTV by about half with no change in price.
For product teams, LTV helps compare segments and features by long-term value rather than first-month revenue. For a method that applies it to individual features, see evaluating feature profitability with lifetime value and retention signals.
Customer Lifetime Value Example
For example, a B2B scheduling tool earns an average of $100 per account per month at an 80% gross margin, so each account contributes $80 a month. Monthly churn is 2.5%, giving an average lifetime of 40 months.
Estimated gross-margin LTV = ($100 × 0.80) ÷ 0.025 = $3,200.
This is a model-based estimate under the stated assumptions, not observed lifetime profit.
The company's CAC is $900, so the LTV to CAC ratio is about 3.6. When the team splits the numbers, small teams churn much faster than larger customers, so their LTV is far lower. The team investigates acquisition and onboarding costs by segment before changing campaign budgets; a blended average alone would hide those differences.
Customer Lifetime Value vs. Customer Acquisition Cost
LTV looks forward at the value a customer will produce. CAC looks back at what it cost to win them. Neither is enough alone: a high LTV is not useful if acquiring each customer costs even more, and a low CAC does not help if customers leave before paying it back.