Correspondence: Timothy L. Keiningham, IPSOS Loyalty Morris Corporate Center 2 1 Upper Pond Rd Bldg D. Parsippany, NJ 07054, USA. Tel: +1 973 658 1719; Fax: +1 973 658 1701; E-mail: tim.keiningham@ipsos-na.com

¹is Global Chief Strategy Officer and Executive Vice President at Ipsos Loyalty. He is author of several management books, his most recent being Loyalty Myths. He has received best paper awards from the Journal of Marketing(twice), the Journal of Service Research, and Managing Service Quality (twice), and has received the Citations of Excellence 'Top 50' award (top 50 management papers of approximately 20,000 papers reviewed) from Emerald Management Reviews. Tim also received the best reviewer award from the Journal of Service Research. His papers have appeared in such publications as Journal of Marketing, Sloan Management Review, Journal of Service Research, Journal of Relationship Marketing, Interfaces, Marketing Management, Managing Service Quality, and Journal of Retail Banking. He serves on the editorial review board of Journal of Marketing, Journal of Service Research, Journal of Relationship Marketing, and Cornell HRA Quarterly.

²is Associate Professor of Marketing at Koç University in Istanbul, Turkey. She is the co-author of the book Loyalty Myths (with Keiningham, Vavra, and Wallard), 2005 by John Wiley and Sons. She has received best paper awards from the Journal of Marketing and Managing Service Quality (twice), and has received the Citations of Excellence 'Top 50' award (top 50 management papers of approximately 20,000 papers reviewed) from Emerald Management Reviews. She was also awarded finalist for best paper in the Journal of Service Research. Her papers have been accepted for publication in such journals as Journal of Marketing, Marketing Science, Journal of Service Research, MIT Sloan Management Review, Journal of Relationship Marketing, International Journal of Service Industry Management, Managing Service Quality, Journal of Consumer Marketing, and Marketing Management. She serves on the advisory board of the Journal of Relationship Marketing, the editorial review board of the Journal of Service Research, and the International Journal of Service Industry Management and is an ad hoc reviewer for Journal of Marketing and Cornell HRA Quarterly.

³is the Dean Samuel B. and Evelyn R. Richmond Professor of Management at the Owen Graduate School of Management, Vanderbilt University. His research interests include the adaptation of grade-of-membership and latent class models for marketing and medical research, estimation of qualitative data reliability, large sample estimation theory, and extreme value theory. He has also written and consulted on models for mortality, medical complications, medical malpractice, and automobile insurance claims. His publications have appeared in business, statistics, and medical journals, including the Journal of Marketing Research, Journal of Marketing, Psychometrika, Journal of the American Statistical Association, Annals of Probability, Circulation, and the New England Journal of Medicine.

⁴is Professor and Chair Department of Marketing. He is founder and director of Service Forum and the founder of The Norwegian Customer Satisfaction Barometer. He won the MSI/H. Paul Root Award from the Journal of Marketing, and has the Most Downloaded Article Award, and the Citation of Excellence Award (twice). He is on the editorial review board of Journal of Marketing, Marketing Science, Journal of Service Research, and the International Journal of Service Industry Management.

⁵is Senior Research Analyst at Ipsos Loyalty. He holds a BA in Sociology from Rutgers University and an MA in Social Research Methods from the University of Durham (UK). Luke has published editorial pieces in the field of International Relations for the School of Government and International Affairs Review, and is currently working on academic and trade articles in market research and applied modern sociological theory. He has also reviewed for East Asia: An International Quarterly.

Received 10 December 2007; Published online 12 May 2008.

Abstract

The measurement and management of customer loyalty and its link with firm growth have long been of interest to managers and researchers. One relatively recent word-of-mouth customer loyalty metric purported that the link to growth is the Net Promoter Score (NPS), a metric based on a likelihood to recommend question asked in customer surveys. This research provides a summary of the claims made regarding NPS, reviews the research conducted on this topic to date, and provides a holistic examination of two scientific studies that test the claims made. The two claims being tested are that (1) NPS is the single most reliable indicator of a company's ability to grow and (2) NPS is superior to customer satisfaction and the latter has no link to growth. Based on both macro- and micro-level investigations that test the link between NPS and firm growth and NPS and customer behaviour metrics respectively, our research finds that neither of these claims are supported.