The NSG is the term i coined to that flickr-oriented website found at www.nikonstunninggallery.com . I started tagging my photos with "nikonstunninggallery" as early as August 2006. I was very much elated when my initial offering was picked by Nikon and that was the portrait of Camille taken at a bar (see lower-most photo).
The NSG site is a Nikon sponsored Flickr gallery of "stunning" pictures shot from, and taken by, a Nikon camera. It is supposed to showcase "stunning" photos from the point of view of Nikon inasmuch as they are the ones who pick and choose which photos qualify to their standards as worthy of being publicly displayed in the NSG website.
Nikon chooses an undetermined number of photos which they feature and add to the gallery once or twice a week. The frequency and the days when they pick the "stunning" photos are invariably unpredictable to make it more appealing and exciting to Nikonians who wishes to see their photos featured and added to the gallery.
Here are some tips that i have logically discovered on how to increase your chances of making it to the NSG. Your photos should have EXIF files showing that it was indeed taken by a Nikon camera (that is obvious, right?) As much as possible, tag your photos with Nikkor lenses you used in taking those photos. Nikon wants to highlight the superiority of their lenses too and they know very well what lenses they have in their archives and what lenses they do not manufacture. I've submitted quite a number of photos taken from Sigma lenses and only one of them was inadvertently picked (i guess) by Nikon.
Since they only select photos once or twice a week, post your best photos tagged with "nikonstunninggallery" three to four days after they made their last pick. No matter how stunning your photos were, if they were posted right after they had already made their selection, chances are, those photos will be overwhelmed by succeeding photos posted right after yours. Nikon only sees the latest posted images first and by the time they have seen your photos, they have already picked and selected several photos as their featured photos of the day.
Avoid putting signatures or watermarking to your photos. Nikon wouldn't want you to be that famous, you know!! Another point to consider is to refrain from too much image manipulation and tag or post only photos that are natural looking or those photos which are minimally photoshopped.
Be considerate to others and let them have a share of the limelight too! When you already have a featured photo on the first page of the NSG, refrain from posting any further. Wait until your photo moved down to the second or third pages and that would be the best time to tag your candidate photos again. Lastly, don't fool yourself - make sure that what you're posting are indeed "stunning" photos from your own honest to goodness assessment!!