http://blog.flickr.net/2015/03/25/the-flickr-commons-welcomes-our-100th-institution/?linkId=13123794
“In total, there are more than 4 million images in the Commons. The collection has been viewed more than 1.3 billion times and the Flickr community has added 53 million tags, 1.5 million faves, and 220,000 comments.”