Churn: how customer attrition translates into revenue lifetime and valuation

Churn is the share of its customer base or recurring revenue that a company loses over a period. For a corporate finance analyst this is not a marketing metric. It is the decay rate of revenue the company has already won. It determines how many years an acquired customer stays, how much of new inflow has to be spent simply on rebuilding the base, and what growth rate can be built into a model without fooling yourself. Until churn has been measured, any valuation of a subscription or recurring-revenue business rests on an assumption that nobody has stated out loud.

What exactly counts as churn

Churn is calculated as the customers lost during a period divided by the base at the start of that period, and this is where definitions already start to diverge. Logo churn weights every customer equally: losing a large corporate contract and losing a cheap tariff plan count the same. Revenue churn weights customers by money and usually comes out very differently, because the customers who leave are typically not the most expensive ones but the lightest.

Analysts also distinguish gross churn from net churn. Gross churn captures only the losses. Net churn subtracts expansion from them: upselling, upgrades to higher tiers and rising usage within the remaining base. This gives rise to net revenue retention (NRR). If expansion outweighs the losses, the base grows on its own without a single new customer, and that is a fundamentally different business profile from one whose growth rests entirely on acquisition.

The third split is between voluntary and involuntary churn. A customer who leaves for a competitor and a customer who drops off because a card payment failed end up in the same metric, but they call for different remedies and differ in how persistent they are.

Why churn costs more than it appears to

Churn works like compound interest in reverse. While it is high, customer lifetime is short, which means customer acquisition cost (CAC) has to be recovered within that short window. If the CAC payback period does not fit into the actual customer lifetime, the company is buying revenue for more than it is worth, and scaling up only accelerates cash burn. The income statement can still look tidy in the meantime, because acquisition costs are expensed immediately while the erosion of the base shows up with a lag.

The second effect is a change in the required rate of return. Revenue with high churn is less predictable, its cash flow is closer to one-off income, and investors discount it more heavily. That is why companies with comparable revenue but different retention almost never trade on the same multiples: the valuation gap is the price of the difference in how durable the base is. Russian issuers' multiples are easy to compare in the equities section, and the profile of a stock such as SBER with its 3,92 reading provides a reference point for such a comparison.

How churn enters the model

In a DCF, churn appears twice. In the forecast period it sets the share of the base that has to be replaced every year just to keep revenue from falling, and therefore the scale of acquisition and retention spending. In the terminal value it caps the permissible growth rate: a business that loses a noticeable part of its base every year cannot grow forever at a rate that contradicts its own retention. Most inflated valuations of subscription models live precisely in this contradiction between a short customer lifetime and upbeat terminal growth.

For businesses where the customer base is effectively the source of the dividend stream (telecoms, subscription services, insurance), churn directly determines how sustainable payouts are: a shrinking base hits the ability to pay earlier than it hits reported profit. Past and upcoming payments can be checked in the dividend calendar —

Where to find the metric for Russian issuers

An honest caveat: the platform has no metric code for churn. It is an operating indicator that issuers disclose voluntarily, not a line in standard financial statements. So the source is always the same — the company's own disclosure:

• quarterly and annual reports and operating releases, collected in the reporting section; churn more often appears not in the financial statements but in the operating section or the investor presentation;
• publication dates and management calls are in the events calendar; that is exactly where it makes sense to ask how churn is defined;
• corporate announcements and changes to the metrics being disclosed are in the news feed. A metric disappearing from a presentation is a signal in itself.

If an issuer does not disclose churn, it has to be estimated indirectly through the dynamics of the subscriber base, average ticket and revenue per customer. Such an estimate remains an estimate, and in a model it is better kept as a scenario range rather than a single value.

What should not be mixed up

Customer churn is easy to confuse with capital outflow, but they operate at different levels. The first describes the behaviour of a particular company's customers; the second describes money moving across a border or out of an asset class. The definition of the second term is in the glossary, and the other concepts of corporate analysis are in the platform's main glossary.

Finally, zero churn is not the goal. A base always loses some customers, and trying to keep all of them means discounts that destroy margins. The managerial purpose of the metric lies elsewhere: to separate the churn the company is able to eliminate from the churn built into the nature of the product, and to put the latter into the model rather than the hoped-for figure.