Originally Posted by UABigBird
I am a t-Mo GSM subscriber and a HS subscriber. The cost is $20 / month without a commitment. I can add or remove it from my account at my choosing. Also, for existing GSM subscribers, the sign up bonuses are not available (5K AA or 5K DL etc...)
That is one of the unwritten tricks.
It is much cheaper to just add and remove when needed than to keep the service on your plan all month.