Customer lifetime value (LTV) is the total revenue you expect from a customer over the whole time they stay. A simple estimate is average monthly revenue per customer divided by monthly churn rate.
A customer paying $20 a month with 5% monthly churn stays about 20 months on average, so their LTV is roughly $400.
Lowering churn raises LTV as much as raising prices does, and is often easier.
Why it matters for a launch
LTV sets how much you can afford to spend to win a customer, which decides which marketing channels make sense.