John Shore:

People in publishing are just like everyone else in the world, and everyone prefers to do business with people they know, or at least people who know people they know. Buy a Rolodex. Get busy emailing, phoning, writing, networking. Be proud; never act like you need anyone more than they need you. But make it so that when as many people as possible do need someone, they think of you.

"My Last, Best 10 Tips on How to Make It as a Writer," JohnShore.com