@Linkat,
I'd pay extra to sit next to someone who doesn't talk to me.
Perhaps we can all get a rating on how nice of seatmate we are. People with high ratings get subsidized by people with crappy ratings.
Leaning your seat all the way back: -1
Helping someone with their bag: +1
Dropping your bag on someone's head: -2
Brushing your teeth before the flight: +2
Farting: -8