As I have said for I don't know how long now, the sporting world has become so much smaller. It's not League against Rugby Union and Australian Rules anymore, it's League up against every other sport played in the world.
Hayne made his decision to try out the NFL, not because of the money but because he wants to test himself in another sport that he has a passion for. The fact that it's played in another country halfway around the world is irrelevant to him.
Thirty or forty years ago most Australians would not have even heard of or known anything about the NFL. Today with cable TV and more so with the internet every sport is beamed in to our homes regardless of where it is played. The NFL has a good number of supporters here and if Hayne succeeds in the NFL then that number will only grow. His success could even open up the opportunity for other Aussies to try there luck in the US.