This document discusses churn in the context of Google AdWords accounts. It defines churn as an AdWords account that has been inactive for 6 consecutive months. The document notes that churn is a detractor of growth and that retaining existing customers is important, as it is easier to sell to existing customers than new prospects. It shares that around half of defined churn cases are potentially controllable through partner actions. The document provides best practices for partners around tracking customer contracts, communicating value through reporting, and utilizing Google's predictive churn program and other tools to support retention efforts.