NFL:  "kill the goose that lays the golden eggs".  From the Aesop's fable The Goose that Laid the Golden Eggs, in which a married couple own a goose that lays one golden egg every day. For greed, they decide to kill the goose to obtain all the gold they suppose to be inside. Once opened, the goose proves to be like any normal goose inside.  In this case the golden eggs are the fans and they are leaving in troves.