Net Promoter Score (NPS) is a simple, widely used metric of customer loyalty. It asks one question, "how likely are you to recommend us to a friend or colleague?", on a 0-10 scale, and derives a single score that predicts growth better than most complex satisfaction surveys.
Respondents are grouped into three categories: Promoters (9-10), Passives (7-8), Detractors (0-6). NPS = % Promoters − % Detractors. The result ranges from −100 to +100. Above zero means more promoters than detractors; above 50 is considered excellent; above 70 is world-class.
Recommendation is a costly signal. Customers who recommend put their own reputation on the line, so a high score reflects genuine satisfaction, not politeness. The single question also gets vastly higher response rates than long surveys, which means the data is more representative of the actual customer base.
The score itself is only half the value. The follow-up question, "what is the primary reason for your score?", produces qualitative feedback that guides improvement. Detractors tell you what is broken; promoters tell you what is working; passives tell you what would move them to promote. Ignoring the follow-up turns NPS into a vanity metric.
NPS is a compact, honest measure of customer loyalty. Used alongside operational metrics like on-time delivery and first-pass yield, it keeps the factory's improvement priorities aligned with what customers actually value.
