I'll start. I get a chance to associate with people who share a common interest. I have become friends with them over the years based first on that common association. Because many of us do not have family members to share our passion for family history, it's often hard to find someone to talk to about it or our research or discoveries. At my local society, we all share those interests and values. I get (and get to give) other things which I will post here later. What can you add?