Net Promoter Score (NPS)

October 24, 2026

Net Promoter Score (NPS) is a customer loyalty metric based on one question: “How likely are you to recommend us to a friend or colleague?”, answered on a scale from 0 to 10. NPS equals the percentage of customers who score 9 or 10 minus the percentage who score 0 to 6.

What is NPS?

NPS was created in 2003 by Fred Reichheld, a partner at Bain & Company (Bain & Company, About the Net Promoter System, accessed October 2026). He introduced it in “The One Number You Need to Grow” in the December 2003 issue of Harvard Business Review (Harvard Business Review, December 2003). Reichheld shared the method so any company could apply it. Net Promoter and NPS are registered trademarks of Bain & Company, NICE Systems and Fred Reichheld.

How to calculate NPS

Bain sorts respondents into three groups (Bain & Company, Measuring Your Net Promoter Score, accessed October 2026):

Group	Score	How Bain describes them
Promoters	9 to 10	Loyal, enthusiastic fans who praise the company to friends
Passives	7 to 8	Satisfied for now, may defect if a competitor’s ad catches their eye
Detractors	0 to 6	Unhappy customers with high churn rates

The NPS formula: NPS = % Promoters – % Detractors. Passives are left out of the formula but still count in the total number of respondents. The result runs from -100 (everyone scores 0 to 6) to +100 (everyone scores 9 or 10).

Example (hypothetical): a spa chain sends a survey after each treatment and gets 200 responses:

110 people score 9 or 10: 110 / 200 = 55% Promoters.
50 people score 7 or 8: 25% Passives.
40 people score 0 to 6: 40 / 200 = 20% Detractors.

NPS = 55 – 20 = 35. Write it as 35, not 35%, because NPS is the difference between two percentages.

Bain uses a 0 to 10 scale for two reasons. Including zero stops people from mixing up the ends of the scale, as they sometimes do on a 1 to 10 scale. Eleven points also give enough choice that people don’t default to the top score for an experience that was merely fine.

Using NPS in marketing in Vietnam

Bain suggests tracking NPS for each business, product, store and customer service team, and for each customer segment. For the spa chain above, NPS by branch or by therapist is more useful than one company-wide number.

Tie the question to a specific touchpoint: after delivery, after a free trial ends, after a support call. For customers who have already transacted, a survey sent through ZNS falls under Tag 2, customer care (Zalo Business Solutions, template rules, October 2026). Add an open question, “Why did you give this score?”, so you know what to fix. Customers who score 0 to 6 should get a call from your customer service team within a few days.

NPS vs related metrics

Metric	What it measures	Data source
NPS	Whether customers say they would recommend you	Survey
Retention rate	Share of customers who stay after a period	Purchase and login data
Churn rate	Share of customers who leave in a period	Purchase and cancellation data

NPS captures attitude; the other two capture behavior. Track them together and you can see whether a segment’s NPS drops before or after its churn rises.

FAQ

What is a good NPS score?

There is no single threshold for every industry. An NPS above 0 means you have more promoters than detractors. The most useful comparison is against yourself, quarter by quarter, with the same question asked at the same point in the journey.

Is NPS the percentage of satisfied customers?

No. In the example above, 80% of customers scored 7 or higher, yet the NPS is only 35, because the 25% Passives are not added and the 20% Detractors are subtracted.

If you want to build NPS surveys into ZNS, email or your CRM and measure them by touchpoint, contact Adtek.