ShareThis does not track statistics for sharing activity on your domain until you replace the default key with the ShareThis publisher key.
Please register to ShareThis to get your Publisher key. You can then copy your publisher key from this page - http://sharethis.com/account/
and replace it on ShareThis plug-in (or alternatively, Click on "Click here to register" link on ShareThis plugin configuration page and follow the instructions)
Once you make this change, you can see analytics for your domain on this page - http://sharethis.com/publishers/metrics-dashboard
If you have further queries, please feel free to contact us.
[ Per forum rules signature moderated. ]