To get your 14 day extended free trial you must first log out of your answers account. Once logged out go to the GameFly homepage (www.gamefly.com). Click the joystick in the upper right hand corner and enter the code you saw on TV.
Free trials are for new customers only. If you are new and want an even better deal, sign up at the URL below and receive a buy one month, get one month FREE special.
Good luck and good gaming. :]