I won't mention the website, but I just unsubscribed from a newsletter, and immediately received this email followup:
"Was this a mistake? Did you forward one of our emails to a friend, and they clicked the unsubscribe link not realizing they were in fact unsubscribing you from this list? If this was a mistake, you can re-subscribe at: "
Jeez. Now it feels like uncomfortable breakup. It's getting awkward. Let's try and end this newsletter relationship amicably.