In business, we often hear that "it is who you know", not "what you know". Well, this is often true for most situations. By having a diverse and quality network at your disposal, you will have a great foundation to accelerate your career or business.
However, the "who you know" doesn't always come into play until you can demonstrate "what you know". By demonstrating a subject matter expertise, you will be able to start building meaningful and long lasting relationships. People naturally gravitate towards others who can provide value.
A good source of new contacts is referrals. The fact that someone took the time to make an introduction says a lot about who you are as a professional. Chances are is that you were introduced because of your character and your expertise.
It is extremely important that others understand your knowledge base so you stand out in the business community. Once that happens, you will become the "who you know" in someone else's network. By adding value to others, your network will continue to grow and provide value to you.
Take the time to beef up the "what you know" so the "who you know" is a natural extension of you. By having both elements, you will be in a much better position to capitalize on your relationships.