I think you could pull this scam off for 1 segment but not a mileage run or even a round trip. I've had my ticket not properly scanned on an outbound leg and then found myself not booked for the return trip. Nightmare.

So I guess if you found an incredible deal on a 1-way trip, checked in online and no-showed you could possibly get credit. But if they cancel you as a no-show and give your seat to someone else you are SOL. So you need a cheap and empty low fare long haul flight.

Not my game but good luck.