That's not a joke.
A Cubs fan, a Cardinals fan, a Red Sox fan, and a Yankees fan are climbing up a mountain, arguing about who has the most loyal fans.
When they get to the summit, the Cubs fan decides he’s going to end the argument once and for all. He yells “This is for the Cubbies!” and throws himself off the side of the mountain.
Not to be outdone, the Cardinals fan says “This is for the Cardinals!” and he throws himself off the mountain too.
The Red Sox fan thinks for a moment, yells “This is for EVERYBODY!” and pushes the Yankees fan off the mountain.
P.S. We need more Yankee cards.