Electronic filing systems. A file is a collection of common data. It consists of related records. Information on each record is listed under headings known as fields eg name, address, age, and occupation. Databases enable information to be stored on the computer thus reducing the stationery and storage costs involved in holding large manual files. More significantly with regard to analysing market data, they have a file searching, sorting and calculating facility which enables specific information to be quickly and easily retrieved, and data to be almost instantly reorganised for specific purposes, eg re-arranging customers in ascending order of sales. The use of databases is commonplace in the marketing departments of most large companies. They can be used to store information about customers’ purchasing habits and to produce letterheads and mailing lists far more rapidly than manual methods. For example, when a customer purchases products using a loyalty or reward card, or when an Internet purchase is made, the business can build a picture of their purchasing habits, in terms of expenditure, volume, nature of goods, etc and store this information in a database. If it is seen that a customer buys nappies over a period of time, then such information can be used to market other baby products to this customer. In addition, they might, one year later, send a mailshot to the customer about toddlers’ toys.