What is customer lifetime value (LTV)?

Customer lifetime value is the total profit a business can expect from one customer over the entire time that customer stays a customer — not just their first purchase. It’s the number that should actually drive how much you’re willing to spend to acquire a customer, because a single sale rarely tells the full story.

Most LTV calculators online are built for ecommerce and SaaS, where cost of goods sold and infrastructure costs meaningfully eat into every sale. A course or membership business is a different animal: once a course is built, delivering it to the 500th student costs about the same as delivering it to the 1st. That changes the math enough that a generic LTV number will understate what your students and members are actually worth.

How to calculate LTV — the formulas

The margin-adjustment step is the one most calculators skip, and it’s the one that matters most for a digital business. Two creators with identical lifetime revenue per customer can have very different real LTV if one is running a 60% margin (heavy affiliate and ad costs baked into cost of sale) and the other is running 92% (self-hosted, low refund rate, organic audience).

LTV for membership sites vs. one-time course sales

These are genuinely different businesses under the hood, even though they often sit side by side in the same creator’s product line. A membership’s LTV is driven almost entirely by churn — a 2-point improvement in monthly churn (say, from 7% to 5%) doesn’t just modestly help, it extends average lifespan by more than half. A course business’s LTV is driven by repeat-purchase behavior and how well you build a product ladder — bundles, higher-tier programs, or a next course that past buyers are primed to want.

This is also where the case for lifetime value shows up most in decision-making: it tells you exactly how much you can afford to spend acquiring a customer through paid channels while still being profitable, which a single-purchase view of the business can’t answer on its own.

What’s a good LTV : CAC ratio?

The commonly cited SaaS benchmark is 3:1 — a customer should be worth roughly three times what it costs to acquire them. Below 1:1, you’re losing money on every customer you bring in through that channel. Above roughly 5:1, it can actually mean you’re under-investing in growth relative to what the math would support.

That benchmark travels reasonably well to course and membership businesses, with one adjustment: because delivery cost is so low, a 3:1 ratio on a digital product business is often more comfortable than the same ratio in ecommerce, where thinner margins leave less room for error if the estimate is off.

Frequently asked questions