Net Promoter Score (NPS) and the Sean Ellis PMF score measure different things. Conflating them is one of the most common measurement mistakes in early-stage B2B SaaS.
What NPS measures
NPS measures likelihood to recommend on an 11-point scale. It is a leading indicator for growth via word-of-mouth, and a useful lagging indicator for overall customer satisfaction. It was designed for enterprise accounts where customer success teams can act on individual promoter or detractor signals.
What the PMF score measures
The PMF score measures depth of dependency — specifically, the percentage of active users who would be "very disappointed" if the product disappeared. It is a leading indicator for organic retention and is most useful when you are still trying to find your core use case.
Why PMF score matters more before Series A
Pre-Series A, the most important question is: does this product solve a problem deeply enough that users would notice and miss it? NPS does not answer this question cleanly because it conflates advocacy intent with satisfaction and is heavily influenced by customer success interactions that do not yet exist at the early stage.
The PMF score, by contrast, isolates the product experience from the relationship experience. A user can give you a high NPS because your founder is attentive and responsive, while still not caring deeply about the product itself. The PMF survey catches this.
When NPS becomes more relevant
Once you have crossed the 40% PMF threshold and are scaling with a defined customer success motion, NPS becomes the right primary metric. At that point, you have validated the product and are optimizing for retention at scale. NPS's lagging, relationship-influenced nature becomes a feature, not a bug, because you are intentionally investing in the customer relationship.
Using both
The best practice for post-PMF, pre-Series A teams is to run the PMF survey quarterly and NPS monthly. Use PMF score to govern roadmap direction, and NPS to govern customer success prioritization. Canviq surfaces both in the analytics dashboard and alerts you when your PMF score drops below 40% in any given cohort — an early warning that a recent product change may have hurt depth of dependency for a key segment.