I get a lot of Emails from sites I either no longer have any interest in - or perhaps purchased something from them.
A few days ago I decided to whittle them down by unsubscribing from every unwanted Email - by clicking the unsubscribe link in the footer of the message.
Yesterday I unsubscribed from two more - and in both cases a message appeared on the screen saying "We are sorry you are leaving us - you will received no further messages" (or words to that effect)
Fine...But :-
I have just received an Email from one of them saying "We are sorry you decided to cancel our messages and possibly miss out on our regular bargains- if you want to reconsider click HERE to subscribe again".