Net Promoter Score (NPS) measures customer loyalty by asking a single question: "How likely are you to recommend [company] to a friend or colleague?" on a 0-10 scale. Respondents are categorized as Promoters (9-10), Passives (7-8), or Detractors (0-6).

NPS = % Promoters - % Detractors

NPS scores range from -100 to +100. A positive score means more promoters than detractors; scores above 50 are considered excellent.

NPS differs from CSAT in an important way: it measures the overall relationship, not a single interaction. A customer might rate an individual support interaction as satisfactory (high CSAT) while still being unlikely to recommend the company (low NPS) due to cumulative frustrations. NPS captures the bigger picture.

The connection between customer service and NPS is well-documented but often indirect. Customer service interactions rarely create Promoters on their own — but they frequently create Detractors. A single terrible support experience can turn a satisfied customer into someone who actively warns others away from the company. This asymmetry means the primary goal of customer service in NPS terms is preventing Detractors, not creating Promoters.

For CX teams, NPS is a lagging indicator — by the time NPS moves, the underlying experience changes happened weeks or months ago. More actionable approaches combine NPS tracking with operational metrics (FCR, CES, CSAT) that can be influenced in real-time.

AI customer service impacts NPS through consistency and availability. When every customer interaction meets a baseline quality standard (no dropped conversations, no incorrect information, no multi-day response times), the Detractor creation rate drops, and NPS gradually improves.

Related terms: customer satisfaction score, customer effort score, customer churn rate