Net Promoter Score (NPS) is a wildly popular tool for assessing customers' likelihood to recommend a company's product or service. As valuable as NPS can be, by itself, the "one number you need to grow" doesn't provide insight into why people will promote (or pan) a product or service. Forrester's Customer Experience Index (CXi) helps solve that problem by adding another layer of understanding. The CXi breaks customer perceptions into three buckets —meets needs, easy, and enjoyable — revealing the fundamental drivers of customer experience success. By understanding how these two important metrics work together, customer experience professionals can use NPS as an overall measure of company health that unites employees and CXi as a gauge of what they did right — for whom and at which point along the customer journey.