When I view the Clickthrough Heatmap reports, some of my mailings show two tags on buttons. What causes that?
The reason some buttons show two tags is due to Outlook recipient clicks. Outlook has different rendering rules than other email clients. Because of this, we wrap button links twice. One link is placed on the text of the button and the other link is placed on the surrounding "button" area. For the same mailing, people who are using Outlook have a slightly different clickable area than other email clients.