The concept "treat different customers differently" is based on the idea that:

The concept "treat different customers differently" is based on the idea that different customers have different needs and possibilities.
This concept is part of the customer liftetime value (CLV). CLV allows companies to segment customers based on profitability and potential . The result is satisfied customers and increased profit.

Different customers have different needs ,possibility and value.

Explanation:

Treating different customers differently is a customer relationship management practice where different approaches are given to different group of customers considering the facts that needs ,possibilities and values of every customers are not the same . It is formed on the basis that every customer is unique, hence a one-fit-all treatment may not be relevant to all

Its purpose is to maximize the value of every customer to an organization.

Customers are grouped into different groups  using a set of criteria for effective management of the different groups.

check the picture below.