To start Industry or Market analysis, you may want to get a list of companies doing the same business, with the help of NAICS (North American Industrial Classification System) number. NAICS codes are assigned by the Commerce Department for collection, analysis, & dissemination of data regarding businesses. Some businesses have more than one NAICS code, but they usually designate one or two NAICS codes as primary.
Some businesses and business publications still use the precursor SIC codes (Standard Industrial Classification)