||The thesis deals with the collection, distribution and sale of information and describes associated problems, e.g. the informational duty or the security of personal data. This thesis describes three types of information services: free, fee-based and value-added information services. It also stresses the importance of value-added information services, denotes a concrete process of an industry analysis (through the "glass industry case study") and illustrates the main working positions, which use the external information sources. At the end, it aggregates the most important Czech information sources into a single list.