Back in 1984 or so, Australian Rules Football was being shown on ESPN, since the network didn't have the rights to any of the major US sports. At the time, Foster's ran a full page ad in a magazine (I can't remember which one), which set out the rules of the game. It was actually informative and helped me follow and enjoy the game. No way it would make me enjoy Foster's, though.
Regarding Quidditch, I find it hilarious that there are obsessive fans for a sport which JKR herself acknowledged was created to make fun of obsessive sports fans (specifically an ex of hers who kept trying to explain the rules of his favourite sport to her despite her manifest lack of interest).
