The basic idea behind a Call Shop business is to have a place where customers can make local, long distance or international phone calls. The main sources of revenues will come from the minutes customers are going to spend on the phone. So it all depends on the rates that you are going to setup, just make sure that they are lower than the ones offered by the providers of international call services.
Citel Technologies , A Voice over IP Phone company that provides VoIP Business Phone Systems. Its Main products include EXTender, PBXgateway, Upgraded Hardware Products, PBX platforms etc.