The customer analysis section of your staffing agency business plan must detail the customers you serve and/or expect to serve.
The following are examples of customer segments: retailers, manufacturers, IT, healthcare, etc.
As you can imagine, the customer segment(s) you choose will have a great impact on the type of staffing agency you operate. Clearly retail customers would want different service options, and would respond to different marketing promotions than IT customers.
Try to break out your target customers in terms of their demographic and psychographic profiles. With regards to demographics, include a discussion of the types of businesses you will serve and key functions served (e.g., business owner vs. HR manager).
Psychographic profiles explain the wants and needs of your target customers. The more you can understand and define these needs, the better you will do in attracting and retaining clients.