The article discusses how to predict and prevent customers from becoming less loyal, or "churners," in a retail financial service company. Instead of focusing on products, they redefine loyalty based on each customer's value over time. By using customer lifetime value (CLV), they can identify customers whose future profits are decreasing and may churn. They also introduce a new way to measure the cost of misclassifying customers. The study shows that focusing on profit rather than just accuracy is crucial for predicting customer behavior in a commercial setting.