Net Promoter Score (NPS) is a metric used to gauge customer experience and loyalty. It is calculated based on responses to a single question rating customers from detractors to promoters. Having a high NPS correlates with improved reputation, customer retention, and business growth. Two case studies show how companies improved their NPS and business outcomes: a service provider increased NPS from insufficient product knowledge and communication, leading to higher customer retention. An insurance company found high NPS correlated with longer policy retention, so focused on improving loyalty.