Definition
Net Promoter Score (NPS) asks customers one question: "How likely are you to recommend us to a friend or colleague?" on a 0–10 scale.
- Promoters: 9–10
- Passives: 7–8
- Detractors: 0–6
Formula
NPS = % promoters − % detractors, from −100 to 100.
Using it well
The score alone says little; the follow-up "why?" and the trend over time say more. Combine answers with behaviour: do detractors use the product differently? Store the score as a user property and compare segments.