I was browsing a furniture website and every second page I loaded pestered me with a splash screen asking if I wanted to register for their newsletter.
After about the eleventh time I got the same pop-up, and closed it, I gave in. I typed in an email address. Truth be told though, it wasn't really my email address. My name isn't bugger and I have no association with off.com.
I was not expecting the website to come back with:
Welcome back! Looks like you've already signed up for our newsletter with this address.