This is interesting way to hold your customer, when they are leaving. In web, it happens all the time. But, I found something interesting hubspot.com did while I unsubscribed them not to get any more mail from them. I’m regular user, more then 3-4 yrs I’m checking or getting all the mails and go thoroughly about the ebooks about online marketing.
That sad face gave me a last messages, how badly they are going to miss me. They wanted to express their gratitude about their customers which is interesting way to welcome you for the LAST TIME. Maybe if the disclose the statistics, a lot customer might have returned from un-subscripton.