Yep, as far as I have read here, it is only a USA promotion,
They come about every other day or two, I haven't used any since they started giving them away just to see how many I would get.
Not to rub it in, to my amazement I am now up to 66 of them in my inventory which will help since I don't plan on buying anymore golf balls til I hit the legend tier so I can try out some legend cally's ;-)