Marketing Management Information Systems are becoming increasingly used by marketing departments to test strategic implications over planned performances. Computers and associated software are some of the tools available to the busy executive. Modern integrated workstations on the manager's desk-top have resulted in an increased recourse to MMIS whereby decision making is easily taken. SARIN has created a powerful computerised system based on the collection of territorial and socio-demographic information, available as a marketing tool to the business community and distributed through a packed-switched network belonging to SEAT. This paper describes the approach set-up by the company in offering a MMIS as a service to the client.