There are now over 100 million Creative Commons licensed images on Flickr.
The post "Analysis of 100M CC-Licensed Images on Flickr" examines what types of licenses are used for those images. Here's a brief breakdown:
- Attribution-Noncommercial-No Derivative Works: 33%
- Attribution-Noncommercial-Share Alike: 29%
- Attribution Non-Commercial: 14%
- Attribution: 12%
- Attribution-Share Alike: 8%
- Attribution-No Derivatives: 4%
In light of these results, the author states:
Thus it would seem that the bulk of photos are licensed rather restrictively. That basically means authors rarely tend to release their works with creative and commercial freedoms. 76% of all photos bar commercial use. At the same time, it means that 24%, or 24 million photos, do allow for commercial use with minimal restrictions. For example, over 12 millions photos are completely free to use, as long as the author of the image is attributed.