However, in a more general sense, it means that someone is staring at a golden opportunity that can be easily achieved and all they need to do is to KTFB and get an easy win.
Announcer: Messi passes the ball to Milito inside the penalty box and Robert Green is off to get some fish n chips! KTFB!!
In life, generally:
Mr. A: That girl is totally hitting on me!
Mr. B: KTFB!!