In the process of reviewing a client's Flickr account with my colleague and fellow Searchlight blogger Brian Brown, we noticed that Flickr has recently added nofollow tags to links placed within its Web site. Flickr has been one of the few social-media entities to continue to offer "link juice" from links placed with user-generated content (in this case photo descriptions), making it a viable entity for improving inbound links to a given site.
While it's understandable that Flickr implemented nofollow tags for the exact same reason other social-media sites have--misuse and spamming--it nonetheless marks another step toward the end of major social-media sites passing on PageRank.
It's not all bad news with Flickr, though...at least not so far. The nofollow tags have not been implemented throughout the whole site. While links embedded in individual photo descriptions are nofollowed, so far, links in Set and Collection descriptions continue to be free of them. Will this change? Only time will tell. SEOers everywhere are certainly hoping not.