“Unique Opened” and “Open Rate” under represent the number of unique recipients because they count only successful pings to our servers.  Blackberries, Text only Readers and all mail readers where the user does not select “download pictures” are not counted.

Total opened includes every time the email is opened and read.  Our experience is the actual  number of  readers is somewhere between “Unique” and “Total” and the actual open rate is at least 50% higher than the reported “Open Rate”.