At least for the time of an ad campaign, where Nikon banners will be displayed on Flickr and a dedicated Nikon gallery will showcase Nikon pictures. Mediapost highlights that it is the first time a major campaign (outside Yahoo! search ads) runs on Flickr. Steve Rubel thinks the move could alienate non Nikon users as photo enthusiasts tend to be loyal to one brand.
I agree. Flickr is a community and therefore belongs to its members, not to a single brand. There is a danger of backlash. While I like the idea and I am sure Nikon will run a great campaign, my advice to whoever is running it is to make sure the campaign is not too intrusive and respect the community spirit, as would any members. Seth Godin's permission marketing principles come to mind: an opt-in to see ads on Flickr for community members is now needed.