Flickr was the first "web 2.0" site. It was the first social network. It was the first really global photo publishing website. So I agree with heyts above. Flickr repeatedly becomes a shadow of its former self, and that is really very sad. It could have been more, but Yahoo just drove it into the ground - they did it slowly enough however that it did remain relevant for a long time, but it missed just about every boat that came along.
Friendster pre-dated it by 2-3 years, MySpace and Facebook by a year.
I have to agree with product50, I am an avid photographer but Flickr was never compelling for me. I would only ever see it when someone would post a link to Facebook...
According to wikipedia, Facebook was actually started the same month as flickr (Feb. 2004). del.icio.us was another notable "Web 2.0" site that did predate flickr.
It was also one of the first metadata rich photo sets that was publicly available. Prior to every large company seeing data as their primary source of income Flickr had their open data API and a lot of interesting science was done using Flickr's images and metadata.
Unfortunately there's really no equivalent pool of photographic content--including CC and public domain content. If flickr were to shutdown, a huge amount of content would be lost.
I sort of agree with you but in another sense it remained true to its roots as a photo publishing platform, mostly, for amateurs. But the mass market was fine with putting some pics up on facebook. And serious professionals have other markets more explicitly aligned with their needs.
Perhaps this could be a clarion call for volunteers to start transitioning the CC and public domain content to archive.org, assuming Flickr gives enough notice that such a shutdown were to occur.
