metrics
Net promoter score
What is net promoter score?
Net promoter score asks one question - "how likely are you to recommend us?" on a 0 to 10 scale - then subtracts the share of detractors (0 to 6) from the share of promoters (9 to 10). The 7s and 8s sit in the middle as a neutral zero. The result runs from -100 to +100.
Also known as: NPS, net promoter
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The demo
Ten respondents. Click any chip to cycle it through detractor, passive and promoter, and watch the score. Notice that landing on "passive" parks them in the middle - neither helping nor hurting.
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Click a respondent to cycle their answer:
Cycle a respondent and watch the score react.
What this demo shows (text version)
Ten respondents, each classed as a detractor (scores 0 to 6), a passive (7 to 8) or a promoter (9 to 10), starting at six promoters, two passives and two detractors. The net promoter score is the percentage of promoters minus the percentage of detractors - here, 40.
Because the total stays at ten, reclassifying one respondent moves the score in equal steps, and a passive sits exactly in the middle, adding nothing to the score either way. Turning a detractor all the way into a promoter moves the score twice as far as a single step, because it removes a detractor and adds a promoter at once. The demonstration is that NPS only registers the gap between the unhappy and the delighted, treating the whole lukewarm middle as a neutral zero.
NPS boils "how likely are you to recommend us?" into one number by subtracting detractors from promoters and ignoring the lukewarm middle entirely. It travels well to a boardroom but only ever hears the extremes, so treat it as a rough temperature check, not the whole story of how people feel.
Each time you nudged someone up a bucket, the score moved the same fixed step - and a passive landed exactly in the middle, pulling it neither way. Turn a detractor all the way to a promoter and it moved twice as far. NPS rewards the whole journey from unhappy to delighted, but treats the lukewarm middle as nothing. It only ever hears the ends.
NPS is popular because it is one number that travels well to a boardroom - and risky for exactly that reason. It collapses an eleven-point scale into three buckets, counts only the gap between the ends, and a single grumpy respondent can swing a small sample wildly. Treat it as a rough temperature, not a diagnosis: it hints at how people feel, never why.
Watch how the buckets distort incentives. A team chasing NPS is rewarded for nudging a 6 up to a 7 (a detractor lost) but not a 7 to an 8 (still a passive), so effort pools at the edges and the middle gets ignored. Pair it with something that captures that middle - a satisfaction score, or just reading the free-text comments people leave.