Subscription Churn and Contribution

Subscription revenue recurs only while customers remain subscribed and successfully pay. Churn describes the loss of subscribers or revenue, depending on the metric chosen; contribution describes what remains after the costs of serving them. Keep those measures separate. A forecast should show the starting cohort, retained subscribers, revenue, variable service costs, and acquisition recovery for each period rather than presenting a single lifetime-value number without its assumptions.

Build a three-period cohort

Suppose 100 customers begin a hypothetical monthly subscription priced at $30. Variable service and payment costs are $12 per paid subscriber-month, giving $18 contribution before acquisition and fixed expenses. Assume 10% of the active subscriber count leaves between billing periods, with no new customers. Paid subscribers are 100 in month one, 90 in month two, and an expected 81 in month three. This is subscriber churn, not revenue churn.

Calculate contribution before acquisition

The three periods generate $1,800, $1,620, and $1,458 contribution, totaling $4,878. Per original customer, that is $48.78 over three months. If acquisition cost is $40 per original customer, the cohort incurs $4,000 acquisition spending and leaves $878 over the modeled window before fixed expenses. It remains short after month two because cumulative contribution is only $3,420. Recovery occurs during month three in this simplified timing model.

Understand the tempting shortcut

With constant contribution and churn continuing forever, a geometric-series model gives contribution per original subscriber equal to $18 divided by 10%, or $180, when the first period is included and future periods are not discounted. That is a strong mathematical assumption, not an observed customer value. If churn is zero, the shortcut has no finite result. A finite horizon is more useful when pricing, service cost, cancellation behavior, or capacity may change.

Separate customer counts from billing outcomes

An active subscription may fail payment, pause, receive a credit, or move between plans. Revenue churn also reflects plan changes and can differ from subscriber churn. Decide whether the denominator is subscribers active at the start of the period and which cancellations count. Add collection failures and recovery costs explicitly if they matter. Do not assume all billed revenue arrives in the bank immediately or that prepaid subscriptions are unrestricted profit.

Use cohorts to update the model

Compare customers acquired in the same period at equal ages and keep promotions or plan types visible. Estimate retention from mature records and test higher churn and service-cost scenarios. Fractional expected subscribers are acceptable in a forecast but should be labeled as expected values rather than physical customer counts. The worked churn rate and price are hypothetical. The model evaluates a stated scenario; it cannot guarantee renewals, acquisition recovery, or a particular business return.

Method references: Shopify: customers reports; OpenStax: break-even and contribution analysis. Accessed October 22, 2026. All dollar figures are hypothetical worked examples.