Net Promoter Score (NPS)
Net Promoter Score is a loyalty metric derived from a single survey question, how likely are you to recommend us on a 0 to 10 scale, calculated by subtracting the percentage of detractors (0 to 6) from the percentage of promoters (9 to 10).
Respondents are split into three groups: promoters who answer 9 or 10, passives who answer 7 or 8, and detractors who answer 0 to 6. Passives are counted in the base but not in the score, so NPS can range from negative 100 to positive 100. The number is a snapshot of stated intent to recommend, which is a proxy for word of mouth and a rough gauge of how a customer base feels.
What NPS does not tell you is why. A single score hides the reasons behind it, so the open-ended follow-up comment is usually more useful than the digit. The metric is also sensitive to sampling, timing, and culture (scoring norms differ by region), so treat absolute values with care and watch the trend over time rather than chasing a benchmark.
NPS and reviews measure the same underlying goodwill from two angles: one is a private survey number, the other is public, searchable testimony. A high score that never becomes a visible review does little for a shopper deciding at the moment of purchase, which is the gap between feeling recommended and being found recommended.