The fast track line is free for F and J passengers. But the higher priority is given to the people who purchase fast track service themselves (Y or J or F class tickets, they don't care which class you fly), this paid fast track service includes personal "meet and greet" at the gate when you deplane, then escort you to the fast track lane, and cut to the very front of the fast track lane, so you never have to wait in line even for one minute.