Before I learned the upgrade game and became an Elite, a friend of mine, said he got upgrades to First class, often. That was when there was a REAL First Class Service!
I asked how this happened. He laughingly stated he didn't know. But he was a tall dark Italian MR. AMERICA from New York kind of stud. I never asked if this happened when he traveled with his wife and 2 wild children. But some how I doubt it, since the wife never confirmed the FC treatment.

I always suspected, that the FA's take care of their friends if they can.