You can track shared links in Google Analytics.

<script type="text/javascript">
a2a_track_links='ga';
</script>

You can track shared links using bit.ly.

<script type="text/javascript">
a2a_track_links='bitly';
a2a_track_links_key='addtoany|R_4ed7bcc558a86d04901bfae7c3a20bb5';
</script>

You can track shared links using awe.sm (and Google Analytics).

<script type="text/javascript">
a2a_track_links='awesm';
a2a_track_links_key='7e9fd830bd2402479a0603c05632f638a3ea76cb241212dd8c95c17a99f3d01b';
</script>

You can track shared links using a custom URL.

<script type="text/javascript">
a2a_track_links='custom';
a2a_track_links_key='http://example.com/abc123';
</script>