If you've been using the Net Promoter Score℠ for a while, you've probably wondered if your survey is biased, right? That question makes perfect sense, because NPS®, like any survey metric, can be biased towards achieving higher scores.
For example, can you trust the Net Promoter Score if the customer who left the feedback is a group of friends or a small number of customers with whom you have a close relationship?
Biases are common in research and sampling, and while it's impossible to completely eliminate them, there are ways to improve the quality and accuracy of your data.
Therefore, if you are concerned about biased results affecting the accuracy of your Net Promoter Score℠, you can take several steps to reduce the effects of responses in your survey.
Check out the main factors that can influence your NPS® and how you can correct this in your business:
Partial sampling
Partial sampling is one of the easiest ways to artificially inflate NPS®, according to the book The Ultimate Question 2.0.
The author himself explains that there are several ways to manipulate the Net Promoter℠ indicator, such as not conducting satisfaction surveys with detractors, segmenting a small number of nearby customers to send the survey, or even excluding responses – which directly influences the NPS® score.
A situation like this ends up providing distorted data that may increase your NPS®, but it won't be connected to your company. Therefore, the end result is an inflated score that generates a flawed view of the integrity related to customer retention for your business.
This means that if your company has a small number of customers or if you have a very close relationship with them, you need to aim for an above-average response rate to ensure that your data is not affected by this.
According to the book "The Ultimate Question" and articles discussing benchmark minimum response rates per survey, the average is around 20% – which, depending on the sample size, is a small number of responses.
For example, if you conduct an initial survey of 100 people and 20 of them respond, it may not be accurate information at first glance – however, if you send a survey to 100,000 people and receive 20,000 responses, that's a large sample size.
Therefore, the minimum response rate varies according to the size of the database being surveyed, and the larger the number of submissions, the lower the response rate should be.
Furthermore, it's important to remember that NPS® should be an ongoing practice for monitoring customer experiencein order to be effective and accurate.
Fear of Retaliation
Fear of retaliation is another point frequently discussed in the book The Ultimate Question, as it commonly occurs in various situations.
For example, if a company has market power, either because it is much larger than its competitors or a technology leader in that segment, customers tend to avoid negative reviews.
Furthermore, a customer may avoid giving a supplier a negative review for fear of reducing their priority in accessing customer service or access to an exclusive customer group.
Another case the author mentions is regarding in-person questions that are often biased because we are not expecting them, or simply out of convenience in not having to develop a long conversation explaining the reason for the dissatisfaction.
For example, if you go to dinner at a restaurant and right after the meal the waiter asks you how the food was – you're very likely to answer that everything was good, right?
However, when your friend asks what you thought of the restaurant, you will certainly be more honest about the quality and service.
Request a score
Nowadays, it's quite common for companies to reward their employees based on NPS® scores.
Although it is a healthy practice that encourages the pursuit of good customer service, it should only be applied when the NPS® system is mature and everyone in the company understands its true meaning; otherwise, it can sometimes become an internal competition that may mask the results of the survey.
Asking for or encouraging high scores only distorts the true feelings of the customer and undermines what should be the main objective of your Net Promoter℠ program – namely, an accurate assessment of customer sentimentso that opportunities for improvement can be identified for your company.
Strategic calendar
A strategic calendar or a specific event can raise your satisfaction score precisely because it deals with the customer's emotions.
For example, if your company launches an exclusive course for clients or an in-person event with leading experts in the field, and then you conduct a satisfaction survey, this will likely affect customer perception and lead to higher ratings.
My point is that this isn't wrong – not at all – but you should approach your research as neutrally as possible, without interference from a specific event, holiday, or market seasonality.
Neutrality will help you ensure insights for your company, without external interference or sudden changes in customer behavior.
Color scale
If you type Net Promoter Score℠ into Google Images, you'll likely find several examples of searches with different colors and smiley faces representing the categories of the Net Promoter℠ system.
While these designs may seem clever for capturing customer attention, many of them end up influencing response behavior, resulting in biased data.
According to studies on the influence of colors on response interaction, there are two ways that do not influence the customer's response: using a neutral/single color or a gradient/gradient scale.
The color scale using red, yellow, and green significantly influences the result, according to studies conducted to verify these hypotheses. See below for the correct application of the colors.
High reward
We've discussed this in other articles, but it's important to remember that a reward can exist, but it shouldn't be the trigger for the customer to respond to the survey. The goal is to make the reward a consequence/surprise for the customer.
If the reward is high, it becomes a factor that considerably increases customer satisfaction levels, due to the principle of reciprocity. In the book itself, the author comments that the reward works like "one hand washes the other," so be very careful when using this strategy in your research.
The example the book gives in this case is about a dealership that offered customers a new set of floor mats and the first service free of charge. Although it's a fairly common giveaway, it ends up influencing NPS® scores.
Another very common example is raffling off travel packages or spa treatments to clients. While this is a great way to boost feedback, it can also affect survey data because it's a highly desirable reward.
Conclusion
As you can imagine, there is no formula to neutralize bias in your NPS® survey.
If you notice any unusual behavior in your score over a short period of time, you should test to identify what might be causing the increase or decrease in your score.
Bias will always exist in surveys, and so will the margin of error. It's up to you and your team to make the NPS® as neutral as possible, in every way, to obtain honest and accurate feedback.
The most important thing to remember is that NPS®, when applied correctly, often yields insights , and it is the company's mission not to neglect it, but rather to educate all departments about the importance of this data source for strategic business decision-making.