The key has 3 components:
1. The blade which unlocks the door and turns the ignition switch
2. The remote which unlocks/locks the door
3. A Radio Frequency ID chip which is NECESSARY to start the car

A key ordered off Ebay will not have the correct RFID chip and therefor cannot be used to start/run the car. Only a dealer can get you the right key. Programing is used only for the remote.