The NRL and AFL might actually have more players. It might just be hard to identify them as they may not appear on lists that people have compiled of players and accounts interested in those teams. Considering how many players there are though, it does look a bit small… though as more Australians are apparently on Facebook, I am not necessarily surprised. Compared to the US, there is a much smaller possible population and less penetration by the service. If we were looking at Facebook, some of this might be a bit different. (Though with Facebook, you have to agree to be friends, so the total people would likely be much smaller. I just think the total number of athletes would be higher.)