In the field of commerce and marketing, the 80/20 rule highlights the fact that, for most businesses, a small segment of the customer base generates the majority of revenue. This is a key indicator of the distribution of business activities. In line with the concept of Pareto’s principle in distribution, it is observed that 80% of revenue typically comes from only 20% of customers. Pareto initially emphasized this non-linear distribution of wealth within the population.

The 80/20 rule is rarely strictly observed, and its relevance varies considerably depending on the industry. For example, it doesn’t really apply in the TV subscription sector, is of little significance in the mobile phone industry, and finds only moderate resonance in the retail sector. In other areas, such as services, a 90/10 rule may be more relevant. When the 20/80 rule is verified, it especially highlights the importance of focusing on the most profitable customers as part of a customer loyalty strategy.