Net Promoter Score, or NPS, measures customer loyalty using one question, how likely are you to recommend this company to a friend or colleague, scored 0 to 10, calculated by subtracting the percentage of detractors from the percentage of promoters.

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‍Why it matters

NPS was developed by Bain & Company consultant Fred Reichheld and introduced in his December 2003 Harvard Business Review article, The One Number You Need to Grow. The core claim was that a single recommendation question predicts business growth better than the more complex satisfaction surveys companies relied on at the time. The metric has been widely adopted since, and also widely debated, since later academic research has questioned whether one question really predicts growth as reliably as originally claimed.

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‍How it's calculated

Scores of 9 or 10 count as promoters, 7 or 8 are passive and excluded from the score, and 0 through 6 are detractors. NPS is usually tracked over time rather than read as one snapshot, and it's most useful paired with an open-ended follow-up asking why someone gave that score, since the number alone doesn't say what to fix.

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‍Its employee-side counterpart

The same 0-to-10 scoring logic gets applied internally as Employee Net Promoter Score, or eNPS, asking staff how likely they are to recommend their workplace rather than a product. It's a separate metric tracking a different relationship, but it borrows the exact same promoter, passive, detractor structure.