One of the best ways you can measure effectiveness of your campaigns and follow-ups is by counting the number of subscribers that clicked links in the messages.
You can do it by using a special click-tracking links instead of the regular ones. After a subscriber clicks a tracking link he or she is redirected to the destination page on your website, plus the click count for this link increases. You can add as many tracking links as you like. Every tracking link has an independent click count.
Click the “Click-Tracking” tab of the "Status" panel.
Click "Add" to create a new link. This brings up a window entitled “Click-Tracking Link”. Type a unique name for the link in the “Name” text box, and the Internet address to which you want to link in the “URL” text box. See below for an example.
To insert a click-tracking link into a message you are editing, click the "Insert Field" toolbar button 
, choose the link from the list, and click "OK". Or you can use the name of the link according to the instructions on the "Click-Tracking Link" window. See Composing Mail Messages for more information.
To see the current click counts, click “Refresh”. After you click the button, the program connects to the click-tracking server and downloads the latest click statistics. You can see them in the column entitled “Clicks”.