Internal sources of data are those which are obtained from the internal reports of an organization. For instance, a factory publishes its annual report on total
production, total profit and loss, total sales, loans, wages to employees, bonus
and other facilities to employees etc. External sources refer to the information
collected] outside agencies. It can be collected from primary as well as
secondary sources; type of information can be collected through census or sample
method by conduct surveys and investigation.
Internal information sources are highly valued, but because the management thereof is often not visible the
costs of managing this information sources are seldom closely scrutinised.
Extуrnal information sources are often perceived as very costly because of
calculable purchase prices.
The most famous in the world of information sellers are companies Questel-Orbit and Lexis-Nexis. For example, Questel-Orbit has over 35,000 subscribers around the world, providing information in the field of intellectual property (the largest and most complete online collection of the world's patents in all fields of knowledge) and business (market information and finances of millions of companies around the world.)
Important role in the collection of information belongs to different marketing communications networks such as the Internet, Infonet, Tymnet, Sprintnet, IBIS, EDGAR, NSFnet, EVnet etc. The most well-known and is the fastest growing network of Internet. Through the Internet you can find articles on various areas of knowledge, directories, databases, technical documentation, competitor information, market information, economic data, the results of market research and more Information.