Morgan and Rego challenge the claims by Reichheld and crew that Net Promoter Score is the single customer satisfaction metric necessary to explain business performance. While their peer-reviewed work does identify measures (e.g., Top 2 Box Satisfaction) that do correlate with short- and long-term success (Tobin’s Q, market share, etc.), their computation of “net promoters” is flawed: it is only a rough approximation of the ratio promulgated by Bain and Satmetrix, based on the “how likely to recommend” 0-10 scale. This shortcoming in the work is pointed out by Timothy L. Keiningham et al. Nevertheless, that follow-up note says
Despite the problems with the Net Promoter and Number of Recommendations metrics, Morgan and Rego (2006) have provided valuable insight regarding the relationship between business performance and other commonly used customer metrics…. We are unaware of another longitudinal study that examines the predictive value of satisfaction and loyalty metrics in such a comprehensive way.
And five years after the publication of The Ultimate Question, I’m waiting to see independent research that backs up its claims.