Think Geek knows the way to its geeky clientele's hearts. Hardly does Randy Munroe (who apparently sucks at taking a vacation) post the above comic than the Think Geek team tweets: "If you read today's xkcd & wondered, 'Does that work on ThinkGeek?' you might wanna try SUMMEROF1987." Sadly, it doesn't zero out your order, but it does take $10 off orders of $50+ with the message, "We know what you did. Now aren't you ashamed?"

Also, they warn, you could still end up with a bobcat.