What is a referrer?
A referrer is another website that has linked to one of your Flickr pages. For example, if someone does a search for something on yahoo.com and one of your photos comes up, their clickthrough from the Yahoo! search results page will count as a referrer. You’ll also be able to see what they searched for in the stat about that referrer. When you look at your referrers, you can click through the link to visit the site itself to see where the link came from, and how your content is represented there. If that link doesn’t work, you can also go to the base domain name and see what that site is about.