NPS without lying to yourself
Net Promoter Score takes 30 seconds to calculate, and most companies still do it in ways that make the number meaningless. Formula, sampling and traps.
NPS is the most widely used loyalty metric in the world. On paper it is simple: one question, a 0–10 scale, a two-step formula. In practice there are dozens of ways to produce a flattering number that means nothing. Here is how to do it honestly.
What NPS actually is
The question reads: “How likely are you to recommend us to a friend or colleague?” Answers on the 0–10 scale split into three groups:
- Promoters – 9–10. They recommend you unprompted.
- Passives – 7–8. Satisfied, but not active.
- Detractors – 0–6. They may actively talk people out of it.
The formula:
NPS = % promoters − % detractors
The scale runs from −100 to +100. In B2B SaaS, +30 to +50 is normal. Apple once sat around +72. A typical bank lands near −10. Airlines are frequently negative.
Where companies fool themselves
1. They ask the wrong people
The classic: send NPS only to active paying customers and quietly skip everyone who churned last month. The number jumps 20 points and means nothing.
Do this instead: define the full population (everyone who used the product in the last 90 days) and take a random sample of it. Not “active users”, but all of them.
2. They ask at the wrong moment
Right after a successful action, a user gives you a 10. Right after an error, a 0. Average those and you have measured noise.
Do this instead: ask one to two weeks after the key event: onboarding, first purchase, a support conversation. Give the product time to behave normally and the user time to form an opinion.
3. They ignore the sample size
At 30 responses, an NPS of +50 and an NPS of +35 are statistically indistinguishable. The confidence interval is so wide that movement in the metric tells you nothing, and yet the report says “up 5 points!”
Do this instead: calculate the confidence interval. A rough rule of thumb: the margin of error is roughly ±10 / √(N/100). At N=100 that is about ±10 points; at N=1000, about ±3.
4. They never read the comments
An NPS number without an open “why?” question is close to useless. Everything interesting lives in the text: what detractors hate, what promoters praise.
Do this instead: always add a follow-up. In Askyo that is a conditional branch in the graph editor: detractors get “What could we do better?”, promoters get “What specifically won you over?”, passives get “What was missing that would have made you a promoter?”
How it works in Askyo
The NPS template already has:
- A 0–10 scale (
scale-numerictype). - Graph logic splitting into three branches by range.
- A different open question on each branch.
- A dashboard showing % promoters, % detractors, the absolute NPS, the confidence interval and a word cloud over the comments.
You do not collect the data in a spreadsheet and compute it by hand. The maths happens automatically, sample size included.
An honest-NPS checklist
- The sample is random, not “our best customers”
- Sample size ≥ 200 for significance (or you report the confidence interval)
- The survey triggers 1–2 weeks after the key event
- There is a follow-up asking why they gave that score
- Trends are read as a 90-day rolling average, not month-on-month
- Results are segmented by plan / channel / device instead of averaged into mush
What to use instead of NPS
NPS is not the only loyalty metric. Alternatives worth running:
- CSAT (“How satisfied are you?”) – immediate satisfaction. Good for support.
- CES (“How much effort did that take?”) – a measure of friction. Good for onboarding and complex flows.
- Sean Ellis PMF score (“How would you feel if you could no longer use the product?”) – a measure of product–market fit.
All four exist as ready templates in Askyo. Run them in parallel and you get a picture with depth instead of one flat number.
Want to try it? Build a survey in the editor, the NPS template is already there.