Turns out: your friend’s friend’s friend can make you fat.

Yes. It’s true, and one of several concepts explored in a very unusual book about the power of social connections and the spread of influence and information.

Connected: The Surprising Power of Our Social Networks by social scientists Nicholas A. Christakis and James H. Fowler does for average people who use Facebook what the book Freakanomics did for people who thought studying economic behavior might be boring. The book shines a light on everyday events and makes you reconsider how the world works.

It’s hard to remember that just a few years ago we couldn’t so easily see our social connections. Since reading Connected, I’ve been looking at the map of my social connections with renewed interest. One of the things the book stresses is your relative position within a particular social network and how this position affects you. Do most of your friends know one another, or do you orbit outside many cliques?

Just yesterday, The New York Times did a story about small businesses using Facebook.

In the context of small business (my writing services, or our grocery), leveraging your social network makes perfect sense. One topic Connected discusses is the power of your “weaker” social connections. Weaker connections are defined as those people you know casually, and with whom you share few, if any, mutual friends. These can be the best source of leads, customers, and clients.

It makes sense: your close friends and family already know you, your skills, or your products. Your weaker connections may also be familiar, but here’s the key: your weak social connections know people who don’t know you, and those people know even more people who don’t know you. So to effectively put out the word you need to access your weak connections.

Personally, I immediately recall two examples of “major” gigs found via “minor” friends.

Lesson? Businesses of all sizes and descriptions need to focus on crafting the right message, and, communicating that message to the weakest of your social connections.