Are You a Benefit to Your Network? Value your contacts and they will value you. Entrepreneurs swear by their connections. But sometimes they swear at them as well.

I was invited to speak at a large conference that encourages and supports entrepreneurs. This invitation represented a good fit between the goals of the conference and who I am.

I accepted, even though appearing at the conference meant flying cross-country at my own expense, paying my own way while there and delivering my talk for free. These were all conditions that usually spell deal breaker for me. But I was happy to make an exception because I saw my participation as a way to pay forward some of my own success and be inspired by other talented, ambitious people on the verge of their breakthroughs. I gave my talk and met some terrific people.

On the flight home, though, one thought kept nagging me: The event had not been worth my time, effort or money. I could not shake the persistent feeling that I had let the conference organizers take advantage of me.

I used my ample time in the air to analyze my thoughts and feelings. By the time the plane touched down at JFK, I had my answer: The conference -- billed as a networking event -- had violated the three commandments of networking. Will I accept another invitation from this group? No way, until its principals clean up their act and build their network fairly.

In light of this experience, however, I am convinced that some people need a refresher about how -- and why -- people build and use networks, beginning with the following three commandments.

Related: A New Model for Results-Driven Networking

1. Be a giver.

Be generous with your wisdom: I accepted the invitation to speak as a way to share my ideas and energy and mentor others who could benefit from my experience. I was happy to do this. I didn't fly across the country motivated by first thinking about the people I could meet who might help me. I knew that in giving a substantive talk at a conference for entrepreneurial folks, I was bound to meet interesting people and learn new things.

Add value: You can receive only after establishing that you have something to give, even if it's just generous words of encouragement. For each new person you meet, don't be eyeing your next conquest. Don't assume that a "quo" will immediately follow the "quid." Call it good manners, good karma or paying it forward, being a giver builds better networks.

Related: In the Digital Age, Relationships Have Become Fragmented. Here's How to Enhance Them.

2. Don't ignore red flags.

The mistake I made in accepting the invitation was overlooking huge red flags that signaled early on that the conference organizers were interested in only what they could get not what they could give.

No one likes a taker or adds her to a contact list. Those who make it in business do so because they act ethically and strive to create win-win situations. Successful businesspeople aim to add value to all parties involved in a transaction, unlike the short-sighted types who are thinking only about themselves and unwilling to give to others. Be on alert to avoid the takers.

After I'd agreed to waive my speaker's fee and not charge for my expenses, instead of receiving a message of gratitude, the next communication was a request to sell tables for the conference dinner. This showed little respect for my time or the considerable in-kind donation I already was providing. When I arrived at the conference, my welcome packet had a $75 credit-card form so I could pay for a digital video copy of my talk.

You can't establish a good networking dynamic without acknowledging your contacts' support. If you suspect that a relationship is all give and no take, get out when you can.

3. Narrow your focus.

Stick to networks allgned with your core business area. Before you begin to expend the effort and energy it takes to build a strong and useful professional network, think hard about what you bring to the table and what you expect others will provide.

Don't go to every networking event. This is time-consuming and tiring. Find a few clubs, seminars or forums with people working at your level of competency or above. This set of fewer people will do more for you (as you will do for them) and you'll find that you have the time to do it.

A good network is priceless. It takes time to grow and effort to maintain. Don't take it for granted or call on its members only when you need something. If you find a network and the only question you receive is "What have you done for me lately?" find the nearest exit.

Related: The Entrepreneur's Secret Handbook of the Favor Economy