Not every SU fan is a perfect STH seat-mate, Marsh. But peddling tickets to rival fans to make money diminishes the home-court advantage and subjects the nearby seat-holders to rival jeering the whole game. It's not the end of the world -- but it's not desirable either.
Last year, some of our "loyal" SU STH-fans sold their FB seats to Clemmies for the November 14th game. We weren't having the best season, for sure. But as an SU fan, I had to sit through the entire game (it was hard enough) listening to a bunch of drunken idiots shouting the entire game. One of them said SU "looked like a HS team", etc, etc. That was no fun.
So .. to the people that sold out to Clemson, thanks a bunch ... I hope the extra cash was worth the misery of me having to sit next to the people you sold to.