PARS always recommends exhausting all possible ways of addressing a clients business queries through desk research before considering field research. A great deal of desk research could be conducted in Iran where extremely valuable information is readily available from a wide range of sources. PARS recommends making use of all available secondary information before going into the field to collect primary ones. Internal data sources have always been a good place to start. Internal data is produced and collected by most well organized firms in their day-to-day operations. Data on sales, advertising expenditure, inventory records, salesperson reports, distribution cost, geographic reach of a firm’s commodities and services, general demographic information of purchasers are just some examples of the types of data that are internally produced and collected. Much information is also available externally.