Included in a mailings report is data on "unique opens" and "total opens". What is the difference between "unique opens" and "total opens"?
The difference is this, If someone opens an email immediately but then opens it again later on to read it again. CiviCRM will mostly likely track both opens. So in the Total Opens column stat that will = 2. However in terms of unique opens given that its the same person opening twice the unique opens = 1.
Hope that helps