How does this compare with acquisition cost?

The ratio between them is the number the business actually runs on, and a common rule of thumb wants lifetime value at three times acquisition cost. What that rule hides is time: a customer worth 373 over twenty months does not pay back a 120 acquisition cost until month four, and the cash for those four months has to come from somewhere. Two businesses with the same ratio and different payback periods are not in the same position at all.

Should I use revenue or margin?

Margin, always, and gross margin after the cost of serving that customer rather than after everything. Lifetime value computed on revenue is a number that cannot be spent: it tells you what passes through the business, not what stays in it. On the figures above, using revenue instead of margin would inflate the answer by nearly half — enough to justify an acquisition budget the business cannot actually fund.

Ten Points of Retention Triple the Customer Lifetime

Published 9/23/2026 · 3 min read · Business tools

Lena Hoffmann — Science & education writer at OneKitly

Mathematics · Physics

Checked against 2 sources

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In short

Average customer lifetime is one divided by the churn rate — the reciprocal of the fraction who leave each month — and that shape is why retention behaves so unlike everything else in a business model. With 85 % monthly retention, 15 % leave and the average customer stays 1 ÷ 0.15 = 6.7 months; on revenue of 80 a month at 70 % margin and a 10 % discount rate, that is a lifetime value of 224. Raise retention to 95 % and only 5 % leave: the lifetime becomes 1 ÷ 0.05 = 20 months, three times longer, and the value rises to 373. Ten points of retention did what no amount of pricing would. The same shape works against you at the other end — dropping from 85 % to 75 % cuts the lifetime to four months, and no acquisition budget can outrun a denominator.

At 85 % monthly retention the average customer stays 6.7 months and is worth 224. At 95 % they stay 20 months and are worth 373. The lifetime is a reciprocal, and reciprocals explode.

The value does not triple, and that is the discount rate

The lifetime went up threefold and the value only by two thirds, because money arriving in month eighteen is worth less than money arriving in month two. Discounting is what stops a high-retention model from claiming an absurd figure: without it, a 99 % retention rate would imply a hundred-month lifetime and a value to match. The discount rate is the quiet parameter that keeps the answer finite, and raising it is the honest way to express uncertainty about whether the retention will hold that long.

One retention rate for everybody is the flaw

Churn is almost never uniform. New customers leave far faster than established ones, so a cohort's monthly retention rises as the fragile members drop away — and a single blended rate averages a first-month cliff together with a long-tenure plateau, describing neither. The blended figure understates the value of the customers who stayed and overstates the value of the ones about to leave, which is exactly backwards for deciding where to spend. Compute it per cohort or per tenure band and the two answers separate immediately.

80 a month, 70 % margin, 10 % discount rate
Monthly retention	Average lifetime	Lifetime value
85 %	6.7 months	224
95 %	20 months	373

Worked with our own calculator

Customer lifetime value (CLV) calculator

Given

Revenue per customer / period: $85.00
Gross margin (%): 70
Retention rate per period (%): 85
Discount rate per period (%): 10

Result

Customer lifetime value: $238.00
Average lifespan (periods): 6.667
Margin per period: $59.50

These figures are produced by the calculator below, not typed in by hand — they are recomputed whenever the tool changes.

Run it on your own figures →

Frequently asked questions

How does this compare with acquisition cost?: The ratio between them is the number the business actually runs on, and a common rule of thumb wants lifetime value at three times acquisition cost. What that rule hides is time: a customer worth 373 over twenty months does not pay back a 120 acquisition cost until month four, and the cash for those four months has to come from somewhere. Two businesses with the same ratio and different payback periods are not in the same position at all.
Should I use revenue or margin?: Margin, always, and gross margin after the cost of serving that customer rather than after everything. Lifetime value computed on revenue is a number that cannot be spent: it tells you what passes through the business, not what stays in it. On the figures above, using revenue instead of margin would inflate the answer by nearly half — enough to justify an acquisition budget the business cannot actually fund.

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Sources

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