Internal information sources and records such as accounting records or customer records provide information about customers, sales, costs, inventories, buying habits and timing, the reactions of distributors, suppliers, intermediaries, etc. As an internal information source data from marketing department include Total sales or sales volume over time, regional sales, Sales volume by market segment, Sales by trade category, Sales volume by type of channel of distribution, Pricing information, Communication mix information, Sales representatives’ records and reports and Inquiries or complaints received. As a common practice, companies use external data for forecasting market trends, benchmarking, validation of internal data and demographic analysis of potential markets. External data may be collected from different “favorite sites” on Internet or alternatively from news software like Bloomberg or Reuters, from daily newspapers, magazines, academic journals relevant for the industry. Companies can also trust data collected by governmental institutions such as TUİK. Or alternatively Eurostat’s statistics or Euromonitor’s research findings are available to the firms. There is a wide variety of statistics or journals and publications on particular trades or industries issued by trade associations, chambers of commerce and other bodies such as Istanbul Chamber of Commerce, or Turkish Exporters Assembly.