A guy walks into a bar and shouts, "When I drink, everybody drinks!". Everybody is cheering him and applauding like crazy.
Feeling great, he finishes his beer, asks for another one and shouts, "When I drink again, everybody drinks again!". Once again, everybody is cheering him, he is the hero of the bar.
When he is done drinking, he pulls out his wallet and shouts, "When I pay, everybody pays!".