What is NPS in UX and product design?
Net Promoter Score is a customer loyalty metric developed by Fred Reichheld and Bain & Company that measures how likely users are to recommend a product to others. It is collected through a single question: "On a scale of 0 to 10, how likely are you to recommend this product to a friend or colleague?" Respondents are categorized as Promoters who answer 9 or 10, Passives who answer 7 or 8, and Detractors who answer 0 to 6. The NPS is calculated by subtracting the percentage of Detractors from the percentage of Promoters, producing a score between -100 and 100.
What does NPS measure and what are its limitations?
NPS measures the likelihood that users will advocate for a product, which correlates with business outcomes like growth and retention in certain contexts. It does not directly measure usability, task completion, or user satisfaction with specific interactions. A product can have a high NPS because users love its core value proposition while having significant usability problems that users tolerate because the value is high enough. NPS is also a lagging indicator: it measures the cumulative impression of all past experiences rather than the quality of a specific interaction or release. It provides no diagnostic information about what is driving the score or what to fix.
How should NPS be used alongside other UX metrics?
NPS is most useful as a tracking metric over time and for benchmarking against industry averages, rather than as a diagnostic tool for UX improvement. For understanding specific usability problems, usability testing, task completion rates, and benchmark studies provide more actionable data. SUS and CSAT scores measure satisfaction at a more granular level. NPS is better suited for business health tracking than for UX improvement. When NPS drops or users leave Detractor feedback, qualitative follow-up through interviews or open-ended questions in the NPS survey is required to understand the underlying drivers.