I have a site dedicated to travel in Canada. I like to provide a suitable photo with each story if possible but I have not personally visited every single location. Instead, I was turning to free stock sites like Stock.Xchng but I found that lacking. Then I discovered the Creative Commons of Flickr. Immediately I found all the photos I could dream of... and users would give them to me for free to use on my site as long as I credit them. Great idea! Here is where I got traffic! I felt it only fair to send them a quick (pre-written) e-mail message letting them know that I was using their photo on my website and providing them with a link to the page where it could be found. Of course each one of those people will click the link to see their photo. So that's a few more targeted visitors for me. What was interesting was that they started to twitter the URL, forward it on to their friends via email and some added my link on their own sites/blogs to "show off" that their photo was being used on a site. My traffic and adsense impressions trippled after adding about 100 photos to my site and i'm seeing the traffic increasing daily. If you are looking for a legit way to get photos and traffic, give Flickr a shot.
Yes, I find this a great way to make traffic. CC is a wonderful thing, providing if you follow the attribution process fairly. Quick question, have you thought about using copyrighted photos? I don't mean steal them, I mean emailing the photographer before using their photo, state your purpose, say what you'll give them in return, and if they will be up for it. Sometimes you will get a response back saying no, but you do get quite a few yeses, and that can lead to hwat you mentioned above.
Good point, I have contacted owners of copyrighted photo's before, and so long as you are not reselling their products and give them credit for their work, they are generally quite happy to help.
It appears even one or more of them "shared" my link on their Facebook pages which has created a ton of traffic with Facebook as the referer. I think it's a great way to help spread the word for quality sites.