I see so its only when upgrading and yet you have the opportunity to buy the phone outright and maintain the data plan. But who wants to pay full price for a new phone?
I as well buy my phones so I'm not tied down at any given time. $600 seems expensive, but if you stick back $25 a month you can buy the new phone out right every 2 years (same as waiting for the upgrade)
Sent from my DROID BIONIC using XDA