Well, we have the quadfecta, friends. A T-Mobile rep just spilled the beans on the inside secrets. One of the most interesting tricks to asking for a rebate both at the store and online. The T-Mo system is apparently not up to the tracking task and will accept both attempts as legitimate. Another tip:

“T-Mobile has a policy that they do not advertise that is called a price match guarantee. This states that they can honor any price that has been printed (advertisement), as long as the terms and conditions are the same as T-Mobile’s. It also states that you can get an account credit if the price of the phone goes down within 30 days. “

11 Confessions of a T-Mobile Sales Rep [Consumerist]