What Tracking 13 Billion Email Opens Can Teach Us About the Current State of Email Engagement from @hubspot2016-02-042016-02-04http://jbc.agency/wp-content/uploads/2018/01/jbc-wallpaper-size-1-e1517418990209.pngJBChttp://jbc.agency/wp-content/uploads/2015/08/542.jpg200px200px