How to Build an Effective Network

I have been thinking much lately about how to build an effective network. There are so many ways to network with people now that it is easy to end up feeling like it is just scatter shot. For example, it doesn't make much sense for me, who sells art glass, to network with someone who sells milking machines for cows. In networking there is a relationship where both sides benefit. Networking means allowance for some competition, because there is balance -- I refer to you and you refer to me.

Tonight I was looking through some of my network. I checked sites that I had listed as favorites on FB and found that many did not refer back to me. That was okay because many of the stores were outside my realm to influence and I probably shouldn't even be linking to the store. There was not really much I could do for them.

I wonder if networking would not be more effective if it was targeted. And if it would not be more effective if there was communication between the networking parties. Networking is give and take. Both sides have something to offer the other. One side may give more at certain times, but there should be some kind of balance. Otherwise it would not be in the best interest of the giver to continue the relationship.

I wanted to ask here what things people considered in building their networks. Do you only network with people selling like things? Do you have personal relationships with your network? What do you do that helps each other? I am trying to get some ideas on how to organize an effective network that can be managed with everyone benefiting. I am new to this type of organization, so could use some good pointers.