To obtain a business support system in which consumer needs is efficiently grasped by sharing various kinds of data about a plurality of sales outlets and auction companies, etc. and data about trends of end users, etc. and costs for business and advertisement, etc. are reduced.

The business support system supports the business of the sales outlets, etc. and it is constituted of a server computer, user terminals of the sales outlets, etc. connected with the server computer and a computer program including a first computer instruction for storing data about tastes and trends of customers which are collected by the sales outlets, etc. into a data base, a second computer instruction by which the respective pieces of stored data are associated with one another so that they are shared among the respective user terminals and for performing processing of processing, re-editing, etc., a third computer instruction for constantly storing data about inventory and prices, etc. of vehicles, etc. held by the sales outlets, etc. into the database and for constantly displaying the data at an updated state by an instruction from an end user computer and a fourth computer instruction for storing data intrinsic to the sales outlets, etc. into the database and for performing processing of processing, re-editing, etc. by instructions from the user terminals.