New and regular customer interviews help your brand evolve. Through new insights, you can sharpen your communication, stay one step ahead of your competitors, or even develop new solutions. But how many interviews are useful with your target group? In this article, we share our experiences and the ideal number of interviews so you can consider this for your next interviews.
Customer interviews must focus on one problem
Many companies invest a lot of time and money in large target group surveys. When commissioning the study, they often think the bigger than better, because after all, a large sample minimizes the risk of bias. However, as Marty Neumeier describes in his book THE BRAND GAP, something completely different is often distorted. Namely the mindset of the marketing team , who are responsible for the development of the brand. Quantitative research provides lots of numbers, but provides few concrete insights into how the brand should position itself.
Quantitative studies can be quite impressive, but often lead to paralysis by analysis when companies want to derive significant initiatives and decisions from them. It is usually better to get an approximate answer to the right question than to get a detailed answer to the wrong question. Instead of investing in a large-scale study, we advise investing the money in several smaller and more effective studies. The best studies are therefore quick and straightforward. They are the best not only because they save time and money, but also because they usually focus on one problem at a time.

How many people should you interview?
Depending on the problem to be solved or what you would like to get clarity on, even a small group provides sufficient insights. For example, when we develop a brand strategy in our Brand Strategy Sprint and test the perception of this positioning, we invite 5 people. Now ask yourself what 5 people can contribute in terms of valuable insights as opposed to a large-scale study. As mentioned above, the goal here is to quickly focus on a specific problem. In our sprint, the task in most cases is to gain clarity on how we want to be perceived as a brand in the future and whether the invited people feel the same way about this desired perception.
A small number already offers the correct answers
Another reason why we only work with 5 people is shown by Jakob Nielsen’s analysis. Jakob is an expert in usage research and has spent many years conducting usability tests for websites. As part of these tests, he has looked at many thousands of customer interviews and asked himself how many interviews are actually needed for a meaningful pattern to emerge. He analyzed 83 of his product studies and found that 85% of the problems could be identified after only 5 customer interviews. Jake Knapp made the same experience in his famous Design Sprint, which is why he recommends 5 participants in his book. We can also confirm that in past Brand Strategy Sprints the best results were achieved with 5 testers. A pattern quickly emerged as to how the 5 people in the target group perceive and feel about the brand.
You need support?
We are happy to support you in your customer interviews with our Brand Strategy Sprint. Together with you and your team, we interview your customers and test your brand to increase your chances of success. Get to know us and book a non-binding meeting.