What is NPS and how to measure it
Net Promoter Score (NPS) is the customer loyalty metric. Learn how to build an NPS survey, calculate the score, and improve your business.
What is Net Promoter Score (NPS)
Net Promoter Score is a customer loyalty metric created by Fred Reichheld and Bain & Company in 2003. It measures how likely customers are to recommend a product, service, or organization to their peers. NPS is used by companies worldwide — from startups to Fortune 500 corporations — as a key indicator of satisfaction and future growth.
The question at the heart of the NPS survey
NPS is built around a single question: "How likely are you to recommend [company/product/service] to a friend or colleague?" Respondents answer on a scale — the international standard runs from 0 to 10, while the kazva.bg platform uses an extended 1 to 100 scale for greater precision. This one question is enough to split customers into three categories and give a clear picture of loyalty.
The three categories: Promoters, Passives, Detractors
Based on the rating given, each respondent falls into one of three groups:
- Promoters — a score of 9-10 (or 80-100 on the kazva.bg scale). These are the loyal customers who actively recommend your business and drive organic growth.
- Passives — a score of 7-8 (or 50-79 on the kazva.bg scale). Satisfied but unenthusiastic customers. They can easily switch to a competitor.
- Detractors — a score of 0-6 (or 1-49 on the kazva.bg scale). Unhappy customers who can harm your reputation through negative reviews.
How NPS is calculated
The formula is simple: NPS = % Promoters − % Detractors. The result ranges from −100 (everyone is a detractor) to +100 (everyone is a promoter). For example, if 60% of your customers are promoters, 20% are passives and 20% are detractors, your NPS is 60 − 20 = +40. Try the calculation with our NPS calculator.
What is a good NPS
Interpretation depends on the industry, but the common benchmarks are:
- Above +50 — excellent. Your customers are highly loyal.
- +30 to +50 — good. Your business is on the right track.
- 0 to +30 — there is room to improve.
- Below 0 — critical. More customers are unhappy than happy.
For the Bulgarian market, average values are often lower than in Western Europe, which makes every positive value meaningful.
How to build an NPS survey
An effective NPS survey is short and focused. The core principles:
- One core question — the recommendation scale. Don't overcomplicate it.
- One open question — "What could we improve?" This question turns a number into concrete feedback.
- The right moment — after a purchase, after service, or at a specific interval.
- Anonymity — guarantee it to get honest answers.
Why NPS matters for Bulgarian businesses
In a market with a limited customer base, retention is cheaper than acquisition. NPS provides an early signal — before the customer leaves, before the negative review shows up on Google. Bulgarian companies that track NPS regularly can react proactively: identify service problems, optimize processes, and build a real competitive advantage through customer experience.
How kazva.bg automates NPS
kazva.bg removes the manual work from measuring NPS. QR codes at physical locations let customers rate in seconds — no app, no registration. The platform calculates NPS in real time, breaks the data down by location, period, and employee, and sends alerts when scores drop. The result: a continuous stream of feedback instead of one-off annual surveys.