I found this via the guys who wrote 'Made to Stick'. Their thinking on why this promo works - it's unexpectedness. For those who haven't read the book - if you sell anything you will find it interesting - the other principles of 'stickiness' from the book are simplicity, concreteness, credibility, emotion and storytelling..... or tah dah....'succes' (you would have thought they'd have come up with one more principle starting with s?). It's a pretty good book that will make you think. It's chock full examples so I find it interesting that the one example that 'sticks' for me is about Norah Ephron's first day of journalism school. Asked to write the lead for a newspaper story, the teacher provided these facts: "...the principal of Beverly Hills High School announced today that the entire high school faculty will travel to Sacramento next Thursday for a colloquium on new teaching methods. Blah, blah, blah.....". What's the right lead for this story? 'There won't be any school on Thursday'. What's the point? Stickiness is about finding the point, not regurgitating the facts.