Matt
(AddThis Happiness Specialist)
Mar 05, 2012 11:21AM EST
Colin,
It depends on the button. Not all services provide an API we can connect to seamlessly -- whereas if you use our API to include pinterest's counter (e.g., <a class="addthis_button_pinterest"></a>) we can guarantee we'll be able to count. (As of this writing, we can recognize Google, Facebook and Twitter's official API integrations, as long as we're on the same page.)
Check out http://support.addthis.com/customer/portal/articles/381237-third-party-buttons for more information.