Most telecom company's have sweet talking telemarketers who will call and straight off start asking questions about how often you call long distance, how do you call etc...
This is all a scam. At first they will not give you opportunity to ask any question, and then they will offer you some too good to be true scheme (like 4-5 months of a lot of free international call minutes or 4cents a minute) and insist you sign up for it....
Please be careful of such scams. There will be many hidden charges and you will get a big fat bill!
Always, if you are tempted, ask them to mail you some brochures you can read and make up your mind..don't believe their word on the phone.

I was scammed like this by Verizon when I was new to teh country and now MCI tried to pull this same stunt on me but I was wiser after having paid huge sums of money to Verizon!

I just want to warn other people.