It says this on channel 7 news article

Free iPhone 6 from Verizon...what's the catch?

The iPhone 6 won't go on sale until Friday morning, Sept. 19.

But already, the nation's second largest carrier for iPhones, Verizon, is offering it to customers free.

If you qualify, you won't have to pay the standard $199 with a 2-year contract.

What's the Catch?

To get a new 4.7" iPhone 6 free, Verizon says you need to trade in a working iPhone 4 or 5 model (4, 4S, 5, 5S, 5C), and sign a new 2-year contract with Verizon.

If you do that, Verizon will give you a $200 gift card, which makes the new phone free. (It also makes the even bigger iPhone 6 Plus just $99).

Can anyone tell me what this means and how it works?