8fcb62ec_rics___Introduction___FT_Press__Considerations
[0] 2.8 [Metric] Willingness to Recommend [Construction] Generally measured via ratings across a 1–5 scale. [Purpose] Shows strength of loyalty, potential impact on others. [Considerations] 
Nonlinear in impact.
Marketing Metrics: Understanding Market Share and Related Metrics | Introduction | FT Press
Considerations