Possible Duplicate:
Are 'share this' buttons really effective?
Many websites include 'sharing buttons' (Twitter, Facebook, etc.) on their websites these days. I'm wondering if anyone has pointers to statistics that show people actually use these buttons. When i Tweet a link or post something on Facebook i usually just copy the URL, but i suppose some less tech-savvy people might find these buttons useful.
I'm not that interested in opinions whether you should or shouldn't use these buttons, i'm interested in actual statistical data that shows if and how these buttons are used.