I'm on a quest to find the most economical way to upgrade a cellphone on my AT&T family plan. It's been 22 months since acquiring the 24 month contract. I'm eligible.

I'm intrigued by the new Amazon Wireless that launched this week. Currently, Amazon Wireless offers the ability to purchase a new phone with either a new contract or an extension of an existing contract through AT&T or Verizon. Plus, most of these cellphones can be purchased for a penny; and they're good cellphones at that. I know there's a catch. There is a catch, right!?

The fact is, I went through the entire purchase process -- all the way up until the "click for final purchase" button appeared on my screen. And my total? Still a penny. There's got to be a catch. The only thing the fine print said besides the normal mumbo-jumbo, was that 'I am agreeing to extend my contract for two years from the date of the phone purchase.' Easy enough.

Apparently, I don't get it. What's the catch? If you know more about Amazon Wireless, would you mind sharing?