'Every photo was taken somewhere. That's almost always part of the story of the photo,' said Stewart Butterfield, general manager and co-founder of Flickr, which now houses 36 million geotagged photos--roughly 3 percent of its total archive.
I remember when Microsoft's WWMX had 10,000 geotagged photos and it was a big deal. 36 million is still a drop in the bucket of all online digital photos, but it is likely an enormous lead that Flickr now has over any other online photo site. This is one of those situations where more content makes their services more valuable, so new content tends to go to that service -- a positive feedback loop that sets up Flickr/Yahoo! to be the dominator in location related services for consumers.