ozbash said:soccer is the #1 growth sport in nz.
So was basketball in Australia in the 80's and 90's. Anyway, what people play and what they watch are 2 different things. It seems the asians like their soccer because they aren't into the body contact thing (except sumos...!!) so the growth there is not surprising. Non-contact sports such as basketball (throughout asia) and baseball (in Japan) have been boom sports in this region due to their non-contact nature.
Back to my main point, many are not physically suited to playing League so they play soccer, hockey etc when growing up. This is not to say that they don't support a League team and follow the game passionately due to the same reasons they don't play it themselves.
I'm sure there are many more registered soccer players in the US but NFL is the No.1 spectator / TV sport.