A warning about the free month.
IT MAY NOT BE FREE.
When I sold cell phones the contract for all carriers said you were responsible for the usage during the trial period. Most sales people will not tell you that. They are trained to tell you it is a free month when actually it is a get "out of the contract" month.
Also if you take your phone number with you and you don't like the service you will not get your old plan back if you go back to your old provider. Some older plans are much better than the new ones. I had one customer with 1000 minutes and all incoming free for $35. He went with sprint, didn't get coverage and when he tried to go back to USCC he lost his old plan.
Cell companies will stick it to you if they can.
Needless to say i was a horrible sales person.