The power of teams, networks, and other groups is that they gain their strength and value from the pooling of their knowledge, experience and brainpower. But two of the greatest assets each member has are their external networks, and trust.

Let’s say you’re a member of a small group of book enthusiasts, the Left-Handed Geeks Sci-Fi Book Club. You meet once a week and have a great time sharing and talking about your favorite book. Nothing wrong with that, but there’s a wrinkle. Each of you owns only one book (Joe Carbine vs. the Amazon Vampire Babes From Venus), not once in all that time has there ever been a non-member join you, and no one ever buys a new book – you just reread and talk about the same book at every meeting.

Doesn’t sound like much fun does it? In fact, it sounds almost… Twilight Zone. What’s wrong with this picture?

Ed Brenegar over at Leading Questions has put together a chart that illustrates how information flows through a social network. This might be useful information to really get a handle on, if only to help us realize the value of external links to any network. The more links a person has on the outside, the more useful they are to the other members.

But there’s something else as well. As members get to know each other, they begin to build trust. Once trust is established, then any external link or information brought in by that trusted person is automatically given a much higher initial credibility. The opposite is also true: no matter how valuable the information we bring, without trust it’s a hard sell.

There’s an element of responsibility here that cannot be overlooked. Why do so many people follow what bloggers like Seth Godin or Robert Scoble have to say? Because their audiences trust them. Big responsibility, yes?

So what’s the takeaway here? That trust building is an essential activity that will reap dividends for anyone. Marketers know it; politicians know it; CEOs know it – why don’t we all know it? After all, no matter how big a cheese we think we are, if no one trusts us, then even when we think we’re a Gouda, everyone else knows we’re really a… Roquefort.