Don’t be shy when joining networks.  Join three or four different groups.  By not limiting yourself to one group you have opened the doors even further.  The best way to take advantage of this technology is to broaden your senses.  You can network in a particular industry, but don’t limit yourself to that.  There are general business discussion groups that help you reach people outside your industry.  Play the numbers game.  The more networks you join, the more people you will meet.  Madison Who’s Who is effective because it helps you reach people in all industries.