Don't get us wrong, wishing someone a happy birthday on Facebook is a lovely gesture, especially considering the all of 4.5 seconds it takes to write a note on the celebrant's wall. But it's always an interesting spectacle to see which strangers (you don't really know 742 people) come out of social media lurking to make sure you know they're thinking about you on this very special day.

Enter Kate and Riki, the funny duo behind IFC's Garfunkel and Oates [1], here to show you just how much thought you should put into these missives for perfect strangers.

That girl you exchanged a set of midterm notes with in high school chemistry? The colon parentheses smiley face shows you still appreciate her help during finals week '06. The friend of a friend you always see at house parties but never actually hang out with? Throw in some extra exclamation points to show how cool you think they are. It's a fine line between too little birthday effort and way too much.