"The one thing you should you do after you meet someone is add them to the right cluster (i.e. – segment). Most people treat their networks as one large connected cluster. The reality is that it is a set of many clusters.
This is critical because of relevancy. When you have a new article you want to share, a person you want to make an introduction for, or a dinner you want to invite people to, there two very likely possibilities:
The opportunities are only relevant for a small segment (i.e., common passion, specific industry, location, etc.) of your network.
Many of the opportunities you come across are relevant to the same few segments again and again.
The beauty of these two points is that if you find the segments that are relevant for your network, you can organize people into lists that you can reference whenever you need to.”
— The One Thing You Should Do After Meeting Anyone New via Forbes