This is a little trick I learned a few months ago.
No big deal, but it is quite useful if you ever want to know how many times a website has been shared on Facebook.
To do this, simply put this address into your browser:
http://graph.facebook.com/http://www.mywebsite.com
... and replace the part in bold on the website that you want to analyze.
You will get a very basic interface, but will tell you exactly how many times a website has been shared on Facebook in recent weeks ..