Well, if they switched to rugby, then they could play internationally against established rugby teams.
But I'm not sure American broadcasters could adjust to a game with only two halfs of 40min each, no stopping of the clock and nowhere to stuff their abundance of ads.
I wouldn't mock the Americans too much for their famous love of advertising. I haven't found a sport yet that is as much a slave to advertising as Aussie Rules. Try to find a square meter of space[1] at an AFL game without advertising - even the ball itself is adorned with the golden arches.
[1] Okay, some of the grass doesn't have advertising on it.....
But I'm not sure American broadcasters could adjust to a game with only two halfs of 40min each, no stopping of the clock and nowhere to stuff their abundance of ads.