Net Promoter Score NPS (relationship NPS "rNPS"; transactional NPS "tNPS")
A loyalty index from one question, how likely you are to recommend us, scored as the share of fans minus the share of critics.
The fork, why two teams get different numbers
NPS has a fixed formula (Reichheld / Bain) but two live variants and one
persistent misuse. Variant: relationship NPS (asked periodically about the
overall relationship) vs transactional NPS (asked after a specific
interaction), same scale, very different populations and numbers, routinely
conflated on one dashboard. Misuse: NPS is a net count on a -100 to +100
scale, not a percentage, yet it is constantly reported and compared as if it
were "45%". Some teams also silently re-bucket the 0-10 scale (treating 7-8
as promoters), which is no longer NPS.
The trap
NPS is volatile on small samples and a single number hides its shape, a score of +30 can come from an all-passives book with a few promoters, or from a polarized 50-promoters / 20-detractors book that is far riskier.
- The full trap, worked on a real export
- Every formula variant, spelled out
- The reconciliation anchor, what to tie it to and when to refuse
Reference: Reichheld / Bain & Company (2003) - The One Number You Need to Grow, Harvard Business Review