The link list shows the dynamic content tag that you should use to insert that link into your messages.
When you include a link in your messages, the subscriber does not see the actual URL. Instead, they see a link to one of the Email Autoresponder scripts.
http://www.yourdomain.com/ea/t.php?l=4
When they click that link, the “clicks” counter is incremented and the subscriber is redirected to the URL you entered in the link's settings.