One great way to build your network marketing business is to get referrals. There are many sources of referrals, including your own customers, and prospects who turn you down. It is also valuable to develop a network of business owners in your area. As you get to know business owners (a local accountant, gym owner, painter etc..) you develop a group who can truly share prospects together. The more you refer people to their business, the more they will refer people to you.
Here is a great post from Duct Tape Marketing about the value of the network.