In your journeys across the web, you probably have encountered the now ubiquitous question “How likely are you to recommend this website to a friend?” It is the question behind the net-promoter score, a customer-loyalty metric that is often used as a gauge of your user experience. The net promoter score is a customer-loyalty measure obtained from customers’ self-reported likelihood of recommending a service, product, or experience to friends or family.

Definition: The net promoter score (NPS)is a metric that quantifies how many more people are likely to strongly recommend your site or product compared to those likely to criticize it.

Calculation of NPS

NPS计算通过询问人们提供一个答wer, on a scale from 0–10, to the question: “How likely are you to recommend this website/product/service to a friend or relative?” The answers are then grouped into 3 categories:

  • Promoters:responses of 9 or 10, which indicate high satisfaction and strong likelihood of recommendation
  • 批评者:0到6的回应,表明不满和可能的批评
  • Passives:responses of 7 or 8, which indicate moderate satisfaction, but low likelihood of recommendation

The NPS is then calculated by subtracting the percentage of detractors from the percentage of promoters:

NPS Equation

Note that the passives are included in the total number of respondents, but do not contribute to the score otherwise. The rationale is that these users may feel that their needs are fulfilled, but will not actively promote the product or service with family or friends.

It may seem harsh to limit promoters to scores of 9 or better and to count a 6 as a detractor, even though it’s above the mathematical midpoint of the scale (5). However, these cutoff points are actually pretty reasonable because raters tend to be generous and give fairly high scores. For example, the following chart shows the average user satisfaction scores for 42 websites that we tested in 2016:

Web User Satisfaction Scores

You can see that the vast majority of websites were rated 7 or 8: this indicates that 7 is theexpectedlevel of satisfaction on the web today. Most sites are well designed, but that is not good enough: users become active promoters when the site not only见面their expectations, but also超过他们。

从数学立场来看,您可能希望平均网站评级为5.但是,在我们的研究中,我们测试的42个网站的实际平均分数为6.97。(这些网站来自大多数主要的业务领域,并具有各种各样的可用性。)换句话说,给定用户对他们的评级慷慨的倾向,7是perceivedmidpoint on a 0–10 scale.

Interpretation of NPS

NPS can range from -100% (only detractors) to +100% (only promoters). A positive score indicates that the promoters outnumber detractors, while a negative score shows poor customer loyalty, with detractors outnumbering promoters. While that is the full range of possible outcomes, in practice the range tends to be more restricted: in astudythat looked at 20 different software products, Jeff Sauro found that the NPS score ranged from -26% to 40%, with an average of 15%.


Frederick F. Reichheld, a business strategist and author of the bestsellerThe Loyalty Effect, first introduced the concept of NPS in哈佛商业评论in 2003. In that article, he described a 4,000-respondent survey in which he asked several questions and tracked how well the answers correlated with a number of different measurements, including repeat purchases and recommendations to friends or family. He found thatthe question that best predicted customer behavior是净推动者得分。随着时间的推移,NPS也与公司增长强烈相关。

Reichheld argued that the net promoter score is relevant because customer recommendations and word-of-mouth referrals are a direct driver of revenue growth in many businesses. As Reichheld put it, “When customers act as references, they do more than indicate that they’ve received good economic value from a company; they put their own reputations on the line. And they will risk their reputations only if they feel intense loyalty.” This intense loyalty ultimately saves money on marketing expenses and also raises profits over time.

How NPS Can Benefit a User-Experience Assessment

NPS iswell-known and liked by upper management为了其与利润的强烈相关性以及纯粹的事实,即顾客忠诚度是一种愚蠢的东西的可量化测量。

NPS也是如此fairly easy to collect: unlike other more complex instruments, the NPS is based on a single question, so users will bemore likely to actually respondto that one question than to a lengthy survey.

因此,在用户访谈,调查或甚至可用性测试会话中包含NPS,它变得习惯。UX从业者经常使用它作为促进其公司高级领导的买入的工具。在投资于UX过程后,展示客户忠诚度(以及因此,未来销售和利润)的数字更有可能比定性数据更有可能摇摆不持怀疑态度的经理和管理人员。因此,NPS可以是一系列指标的一部分,以测量重新设计的忠诚度。通过在重新设计之前和之后量化的站点可用性和忠诚度,公司可以评估重新设计是否值得,是否带来足够return on investment(ROI).

It’s been shown that NPS is closely related to the perception of user experience. In particular, scores on elaborate satisfaction questionnaires such as the System Usability Scale (SUS) are与NPS相关。Thus, if most of your customers are reporting high loyalty to the point of putting their own reputations on the line to recommend your site, chances are that your site is also usable.

Limitations of NPS as a Usability Metric

1. NPS does not capture the full picture when used in isolation.

Usability is never entirely captured by subjective scores。我们看到许多用户在努力完成任务,但并像没有任何困难的人一样评级该网站。要获得用户体验的完整图片,我们建议您还收集性能指标,如任务成功率和任务时间。

与所有定量度量一样,NPS告诉您您的网站是如何做的,而不是为什么。要求客户报告其评级的原因可能会有所帮助,但是self-reporting is rarely reliable而用户可能不会打扰投资时间来解释评级。

2. NPS is only relevant with a large enough sample size.

NPS scores (like any metrics) are rarely relevant with a small sample size. Running a使用5个用户进行定性用户测试and asking for the NPS at the end is unlikely to provide you with any valid data, yet many practitioners insist upon reporting these measures with small samples and they base design decisions on them, disregarding their lack of statistical significance.


While other satisfaction metrics also suffer from the disadvantages mentioned above, NPS has another major problem: its calculation method ignores a lot of the information provided by the ratings by grouping them into three bins (promoters, passives, and detractors) and then ignoring the passives. As a result, researchers must drastically increase their sample sizes in order to gain any statistically relevant information, and even then, researchers lose sight of the intensity of a respondent’s score.

For example, if we could change a design from getting mainly scores of 2 (truly hated) to getting mainly scores of 5 (somewhat disliked), we would have made a major UX improvement, but all of those users would still be counted as detractors in NPS terms, even though they had changed from being rabid detractors to being modest detractors.


NPS is best used to assess overall customer satisfaction with an entire company or service, or at least with an entire product. It makes less sense to utilize NPS to assess user satisfaction with lower-level details of UI design, such as a website’s checkout process, a product page, or a specific dialog box or icon. Yet these local design elements are often what we can actually change in everyday design projects. And these details sum to form the overall impression a customer has of a company.

有许多例子的例子UX design decisions impact brand perception— for example, thespecific location of a logo on the web pageimpacts whether users even remember the brand at all, or thetone of voice employed on the website changes users’ inclination to recommend该公司在网站后面。


Let’s say that you improve the writing on some web pages or that you improve theusability of the icons在移动应用程序中。如果公司的整体NPS保持平坦,不要太失望。单一本地化设计决定将针对整体客户忠诚度大大移动。这就是为什么我们需要补充全球NPS分数,具有较低级别的用户满意度和任务性能的措施。




Frederick F. Reichheld. 2003.The One Number You Need to Grow哈佛商业评论