Using NPS® for a Targeted Customer Approach

Case Study


How KELLER Group Multiplied its Average Sales Value through Experience-Based Customer Approaches

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The relation between customer satisfaction and company success seems clear: satisfied customers lead to repeat purchases and thus more sales—without incurring the associated high marketing costs. This is because customer retention measures generally have a higher ROI than new customer acquisition measures. As a result, many companies have already realized that satisfied customers are worth their weight in gold.

However, the difficulty is often to identify satisfied customers and address them correctly so that they become enthusiastic brand ambassadors. In addition, companies are often faced with a challenge when it comes to identifying dissatisfied customers and encouraging them to give the company another chance. A proven solution? The Net Promoter System®.

The Customer Groups in the Net Promoter System and Their Influence

Platforms based on the NPS® enable companies to gather, analyze, and evaluate customer feedback. On the basis of a simple question, it is possible to identify which customers are very satisfied (also called promoters), which are neither very satisfied nor very dissatisfied (passive or indifferent), and which are very dissatisfied (critics, also called detractors).


This is especially important because satisfied and dissatisfied customers differ not just in terms of their impact on the company’s success but also how they should be addressed :

  • Promoters typically have a larger shopping cart and are responsive to cross-selling efforts
    Promoters usually order higher values and can therefore be used very well for up-and cross-selling campaigns. This also means that turning detractors into promoters can increase their shopping cart size by up to 25 %. In addition, promoters are likely to speak positively about both the company and their products to their friends and family. By sharing their positive experiences, they can be used for referral marketing to support the company’s acquisition of new customers.
  • Detractors are three times more likely to churn than promoters
    This means that if you can succeed in turning detractors into promoters, it is likely to prevent them from ending their business relationship. This not only saves costs—for example, in personnel, as promoters need customer service less often than detractors—but also generates additional revenue as promoters continue to buy from the company. Practice shows: In many cases, former detractors become the most loyal fans and brand ambassadors.
  • Passive customers have great potential for referrals and minimizing customer churn
    Often, passives are the customers that are most frequently neglected. Similar to detractors, however, these neutral customers also generate great potential when they are transformed into promoters. A key factor in this is that, due to their neutral attitude, they are likely to leave the business as soon as a better deal is available. This means that the likelihood of them churning is twice as high as that of promoters. Turning passives into promoters can also increase cross-sell potential by up to 15 % and more than double the likelihood of positive referral. It should be noted that the correct approach can turn passive customers into promoters, but the wrong approach can often turn them into detractors.

This brings up the question: How exactly can you accomplish all this?

The first step is: Collect customer feedback. The second: take the feedback to heart and respond to it. This is where the style of the customer approach comes into play: it should be personalized and tailored to the customer experience. Instead of event-based communication, such as birthday wishes or a reminder after a customer has not shopped in three months, companies should focus on experience-based communication. In this case study, you will learn what this means and how it leads to success.

The NPS and KELLER Group GmbH

KELLER Group GmbH has been collecting NPS feedback with zenloop at two touchpoints since 2017. At the touchpoint “After Parcel Delivery”, they launched a CRM campaign to target promoters, passives, and detractors. The two main objectives of the mailing campaign were:

  1. On one hand, promoters and passives should be encouraged to buy again, especially to buy more products.
  2. On the other hand, KELLER Group GmbH wanted to persuade detractors to give the company another chance and ideally turn them into promoters. It is often enough to listen and indirectly address those customers.

Structure of the Mailing

Over a four-week period, between mid-October and mid-November, randomly selected customers who responded to the NPS query after purchase received a coupon code for their next purchase by mail. Promoters received a postcard with thanks for their positive review, while detractors received an apology for their dissatisfactory customer experience. Customers who rated passively also got a thank you email.

The mailings were based on the reviews that customers submitted after their purchase. That means: Customers who rated scores from 0 to 6 received an apology postcard. Customers who submitted a score of 7 to 10 received a thank you postcard. Overall, the distribution of these customers was as follows: 74 % promoters, 18 % passive, and 8 % detractors.

To illustrate, we compare those customers to another group that also filled out the NPS query after their purchase but did not receive a mailing. In addition, for the evaluation of the case study, we look at all values according to returns, both for the target group and the comparison group.

  1. Customers who received a customized mailing had an Average Order Value (AOV) after returns of € 210 on their next purchase, after having returned all unwanted items. Customers who did not receive mailings, on the other hand, had an AOV after returns of € 80.
  2. Customers from the CRM campaign retained an average of 2.7 products from their orders. Only 14% of this customer group purchased just one item. By contrast, customers not in the mailing campaign, only kept an average of 1.3 products from their orders. A total of 61% of these orders contained only one item.

This shows what is already evident: it is worthwhile to respond to customer feedback. Customers who received a thank you or apology card spent an average of € 130 more per order and kept more of their ordered items.

If you go into a little more detail, three things, in particular, become apparent:

Conclusion 1: The Relevance of Appreciating Promoters

The keyword here is customer retention. According to a study, as many as 60 to 80 % of satisfied customers do not buy again. This means that customers can have a positive buying experience and be very satisfied, but at the same time do not feel connected enough to the company to buy again.

However, if promoters note that their opinion and loyalty to the company is valued—for example, through a simple thank you card or email—they are much more willing to continue to support and shop at this company.

This can also be seen at KELLER Group GmbH: promoters who received a thank you card kept an average of 2.4 items from their order with an average shopping cart value after returns of € 296.

Conclusion 2: The Importance of Appreciating Detractors

If customers who had a negative experience with the company, and were as a result dissatisfied, feel seriously taken and valued, they often become the most loyal fans. Of course, it is important to bring the feedback back to the company and to initiate improvements. However, the numbers show that even a simple gesture of appreciation can make a big difference.

In this case, detractors with an average of 3.5 items in the shopping cart had the highest number after returns and, like the promoters and passives, came to a very high average purchase value after returns of € 257. Without the simple but effective mailing approach, the affected customers would most likely have churned and bought the products from a competitor. Instead, KELLER Group GmbH succeeded in generating additional sales.

Conclusion 3: Do Not Underestimate the Influence of Passives

Although they have great potential when communicating correctly with them, passive customers often receive little attention. However, if these customers feel noticed, their neutral attitude often allows them to be transformed into promoters with relatively little effort.

This is also evident here: AOV after returns were highest for passives compared to the promoters and detractors, at € 331. The same applies to the number of items kept by passives: here the average was three items. As a result, customers who first submitted a neutral review and then received a mailing bought an average of 1.7 items more than the customers who did not receive a mailing. These results clearly confirm that passives have potential and are just as valuable customer groups as promoters and detractors.

This case study shows: it is worthwhile to take on and address customer feedback. It is essential to identify satisfied and dissatisfied customers and to respond to their experiences in a personalized way. In this way, companies show understanding and appreciation of what further binds promoters and passives and can turn detractors into promoters—and thus sustainably increase the company’s success.

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