I happened upon this great Economist graphic on average attendances at major sports in 2013 via a Tweet from JP McCarthy and he made a point that the average attendance at a GAA championship game last year was 19,092.
This perked my interest and so I've added the GAA's figures to the graphic in a way that a child let loose on Microsoft Paint might.
Anyhow, my bad artistic skills aside, it makes for interesting reading. The attendances at GAA matches last year were higher than the MLS, NBA and NHL, and if you rank it by attendance as an average of the overall percentage of the population then the GAA is the 7th best attended sport in the world.
Nothing beats being there, ay?