Check Tell Tale Games and subscribe to their mailing list. Then unsubscribe. Pretty fun text… where they try to convince me to stay. It’s pretty nice idea for “viral marketing”. Their effort got some guy (that would be me) to blog about their site’s mailing list. And this was simply by having a bit different unsubscribe page for a mailing list.
There is indeed possibilities for marketing everywhere. Even when customer is about to step away from your store.