NPS: how to measure customer loyalty with one question

NPS (Net Promoter Score) shows how many of your customers are willing to recommend you to others. People like it because it is simple: one question and a single number you can compare from month to month.

The main question

How likely are you to recommend us to a friend or colleague?

The answer is on a scale from 0 (not at all likely) to 10 (extremely likely). You can make the wording more specific, such as recommend our store or recommend our delivery service. What matters is that the scale runs from 0 to 10, otherwise your result cannot be compared with anyone else's.

Three groups of customers

• Promoters, scores of 9 and 10: happy customers who recommend you on their own.
• Passives, scores of 7 and 8: satisfied, but they will switch to a competitor given the chance.
• Detractors, scores from 0 to 6: unhappy, and they may talk others out of buying from you.

How to calculate it

NPS = % of promoters − % of detractors

Passives are not part of the formula, but they do count towards the total number of responses.

Example. 200 people answered: 90 gave 9 or 10, 60 gave 7 or 8, and 50 gave between 0 and 6. Promoters: 90 / 200 = 45%. Detractors: 50 / 200 = 25%. NPS = 45 − 25 = 20.

The score ranges from −100 (everyone is a detractor) to +100 (everyone is a promoter). It is not a percentage, just a number.

What is a good NPS?

There is no universal benchmark: banks, online stores and cafés all have their own typical levels. It is more useful to compare yourself with yourself: measure NPS regularly, for example every quarter, and watch whether it goes up after you make changes.

The second question matters more than the first

The number alone does not tell you what to fix. So right after the score, ask an open question: What is the main reason for your score? or What would it take for you to give us a 10? Detractors will show you what hurts, and promoters will show you what they value.

How to run an NPS survey in simpoll

1. Create a survey form: see How to create your first survey.
2. Add a rating scale question from 0 to 10 and make it required.
3. Add a long text question: What is the main reason for your score?
4. Send the link to customers after a purchase, or put the survey on your website: how to embed a survey.
5. The results show how the scores are spread. To read only what detractors said, create a filter for scores from 0 to 6.

Common mistakes

• A 1 to 5 or 1 to 10 scale. That is no longer NPS, and there is nothing to compare it with.
• Asking only happy customers. If you send the survey only to people who left a good review, the score will look great and tell you nothing.
• Too few responses. With 20 responses, one person moves the score by 5 points. Draw conclusions once you have at least a hundred.
• No follow-up question. A number without reasons will not tell you what to do.