Curious fact happened on flight LX92 (ZRH-GRU) on day 6th nov 2015.
I am pretty curious to understand what happened and, maybe, turn this experience in my favour...
I got on the plane with priority boarding (due to *Gold status). I went to my seat (23D). The seat next to me (23E) was free during my check in and it remained free till almost the boarding was completed.
At a certain point, a pretty blonde young girl (in her 20s, probably, german speaking) came to the seat 23E. While still standing, she looked around for a long time. She left one of her two small hand baggages on the seat and went to seat in the rear part of the aircraft. Boarding completed, just before the plane began to move, the girl came back on seat 23D.
Apparently she was in friendly acquaintance with a lady member of the crew. After the dinner, as soon as the lights were turned off, the lady crew member came to us, talked with the young lady seated on 23E and, after a short trip toward the back of the plane, they both crossed me again and went into business class section.
The young lady never came back to her (her?!) seat in 23E. The next morning I saw her having breakfast in her new seat (8A or maybe 7B).
Well... I really would like to know how to "play" the same way to get a free business class trip, especially in the route ZRH-GRU as me, neither when I was Miles&More FTL nor now that I am a poor A3*Gold,
never never never got an upgrade on this route...
Anyone could help to explain the facts?