while I appreciate the theory and all other things being equal, I would rather sell to a Ram Fan BUT, I am also not going to float some other less motivated fan because he wears a different color hat. The truly motivated fans will get in regardless. That is why a small contingent of another team can often sound quite loud.
Plus there is nothing better than taking an opposing teams fans $$$ and then they get to watch their team lose.
If I am going to be charitable, I donate my tickets (which I do regularly each year)
All that being said, I have to admit that I do routinely tell people at other stadiums (as recently as Seattle a few weeks ago) when I am surrounded by other teams fans on the road and I say "Don't blame me, blame the a hole that sells tickets to the opposing teams fans."