OriginsThe origins of NPS as a proprietary instrument date to 2001, at which point Reichheld and Satmetrix built on their earlier, ongoing market research efforts to distill and promote a single survey item that was easy to administer to large numbers of respondents, as well as easy for stakeholders to use and interpret. Early efforts to promote the use of the NPS to corporate clients notably include a 2002 Harvard Business Review article by Reichheld entitled ''The One Number You Need To Grow.''
Predicting customer loyaltyThe primary objective of the net promoter score methodology is to infer customer loyalty (as evidenced by repurchase and referral) to a product, service, brand, or company on the basis of respondents' responses to a single survey item. For some industries, in particular annuity-based business-to-business software and services, it has been shown that Detractors tend to remain with a company, while Passives are more likely to leave. The use of the NPS score in addition to revenue retention rates and customer retention rates may offer valuable customer insights and may offer a better predictibility of customer loyalty rates. As it represents responses to a single survey item, the validity and reliability of any corporation's NPS score ultimately depend on collecting a large number of ratings from individual human users. However, market research surveys are typically distributed by email, and response rates to such surveys have been declining steadily in recent years. In the face of criticism of the net promoter score, the proponents of the net promoter approach claim that the "recommend" question is of similar predictive power to other metrics, but that it presents a number of practical benefits to other more complex metrics. Proponents also argue that analyses based on third-party data are inferior to those conducted by companies on their own customer sets, and that the practical benefits of the approach (including a short survey, a simple concept to communicate, and corporations' ability to follow up with customers) outweigh possible statistical inferiority to other metrics."Would You Recommend Us?" Business Week, 29 January 2006.
CriticismWhile the net promoter score has gained popularity among business executives and is considered a widely used instrument for measuring customer loyalty in practice, it has also generated controversy in academic and market research circles. Scholarly critique has questioned whether the NPS is at all a reliable predictor of company growth. Other researchers have noted that there is no empirical evidence that the "likelihood to recommend" question is a better predictor of business growth than other customer-loyalty questions (e.g., overall satisfaction, likelihood to purchase again, etc.), and that the "likelihood to recommend" question does not measure anything different from other conventional loyalty-related questions.Hayes (2008), "The True Test of Loyalty," Quality Progress, June 2008, 20–26.
See also* Advocacy Index * '' The Loyalty Effect'' *