Here, you have access on the opt-outs made by the subscribers.
By evaluating the opt-out numbers you can draw conclusions on how the subscribers react on your mailings. The overview shows the names of all created subscriber lists, the number of opt-outs per list as well as the option 'Open', 'Export' and 'Import'.
By clicking 'Open' you will get a detailed view of the opt-outs of a certain list. Information like email address or opt-out date are stored here.