As far as I understand it, Nikon sell their new product to every one knocking on their door for roughly the same price from Japan.
Some local Nikon distributers seem to be independent such as Nikon USA, some seem direct representations of the Japanese company such as Nikon Europe.
My equipment since I use Nikon starting in 1988, is used or new, local dealer or, later mail order / internet. All of the mix are serviced by Nikon Professional Service here in Germany, no question asked. I am sure that a NPS outlet in the USA would service my items if one of these should fail on a journey. NPS is a worldwide thing, is it not?
In my life I spent roughly 30.000€ to 40.000€ on Nikon Equipment, so Nikon might have earned a few cents from my purchases by now.
What Carl says is important though: Do not buy equipment that will not be serviced in case of service being necessary!
And yes, there can be issues with Nikon equipment, even if the equipment itself is very reliable. I once tried to mount an Ai-S 1.4/35mm in the wrong orientation and destroyed the aperture mechanism of my D600. Cost me 260€ to repair. After a short while the F-mounts of my D3 and a few lenses failed, could be repaired. The D70 failed with "film transport mechanism defect" written on the receipt, a defect inherited from the F80 ... of course there was no film transport in the D70 :-)