NPS & the law of "excluded middle"

In classical Greek logic, there is a principle attributed to Aristotle, called the law of excluded middle. It states that either a proposition is true (or) its negation is true, but there is no middle option. It got us thinking about its applicability to Customer Surveys…….

There are a wide variety of ways to perform surveys: CSAT (Customer Satisfaction), NPS (Net Promoter Score), CES (Customer Effort Score), to name a few. Of these, nothing exemplifies the Aristotlean principle better than NPS. It’s a single question survey that seeks to identify customers’ love, or lack thereof, for your brand/product/service. It asks the following question: How likely is it that you would recommend our company to your friends or colleagues? The respondents score you on a 11 point scale (0–10), with 0 representing Very unlikely and 10 representing Very likely to recommend.

Now comes the interesting part. Unlike traditional scales, which give equal weightage to each score, Fredreich Reichheld (creator of NPS) designed an unequal classification system:

0–6 = Detractor

7–8 = Passive

9–10 = Promoter