That get replaced often too. A D80 owner has their camera for years - a $100 coolpix probably doesn't even last that long and gets replaced by another piece of bling anyway.Probably a factor of there being 27 gazillion different CoolPix models. Seems like there's a different one every two weeks.
But not entirely; it is more the product of [sales] x [activity] and there is likely to be a bias in the latter unless Flickr demographics match exactly Nikon demographics. This explains the relative low score of the D40/D60 as the majority of those cameras are sold to the "soccer mom" customers* who most of the time, if they post images at all, use services like Kodak or the photo sharing that the printing service of their local pharmacy or bulk retailer (Cosco, BJ, Sams, Walmart, Target) provides. In similar fashion "high end" shooters (D700, D3, D3x) likely value presentation more than sharing and will user other services (pbase, smugmug, etc) leaving an overrepresentation of "middle ground" cameras with the D70 at one end and the D300 at the other.I would think those numbers probly fairly representative of sales volumes for each model too