Reference business partners

Hi

We have a scenario of business partners created in different roles and have different sales areas exists. So how do we need to setup reference business partners for customers. Each customer will be extended to only one sales area, but we have almost 10 sales areas. Do we need to create 10 different business partners with each one in one sales area ?.

What is the significance of a reference business partner used for ? and does it copies the data from reference business partner of the sales area of reference business partner.