Net Promoter Score is a customer loyalty metric, used as a predictor of company growth. It serves as an alternative to traditional customer satisfaction research.
NPS is based on a direct question: How likely are you to recommend our company/product/service to your friends and colleagues? The scoring for this answer is based on a 0 to 10 scale, with 9 & 10 classed as Promoters and 0-6 classed as Detractors. The Net Promoter Score is then calculated by subtracting the proportion of detractors from the proportion of promoters.
See also Customer Effort Score (CES) and Customer Satisfaction Score (CSS).