Voip Comparison

what are cost and benefits for a voip provider comparing to normal phone companies ? what are cost and benefits for a voip provider comparing to normal phone companies ? i don't know some cost but benefits might be location is not important example Skype is worldwide but there is no office in example Bahamas but you can still use it there. Please help me with more its important for school

why does the VOIP providers give cheaper services as compared to a normal telephone service provider? voip business...ppl give their phones at a cheaper rate why??? maintenance or the intial startup costs or the operational costs are less????

anyone have voip? which service provider is the best and how does it compare to att?

I would like to know of voip providers in Australia that can provide the service for satellite customers? I am wondering which voip providers in Australia can provide voip for satellite customers in regional and outback Australia? I have herd that there are some differences between using voip in towns with adsl compared to satellite services.