
99.9% of businesses are in the business of selling something, and the person on the other end of the transaction is a customer. Now, different businesses have different numbers of customers: Delta flies hundreds of millions of customers around the world each year (I’m writing this on a Delta flight right now), while a company that creates missile defense systems might do so for very few but usually very large countries over the course of a given decade. Most of these companies also experience what’s called “churn.” The term is most often attributed to companies that sell a subscription, but is also present in most other types of business, just with differing amounts of importance.