answer:I think they live and die by the quality of their communities. That requires social engineering. There is a complex relationship between interface, rules, and community culture. You need to know what you are doing. There are a lot of people out there who are technological wizards, but they are community-building amateurs. Or worse, they don’t even know there is such a thing. People who are smart will recognize where they have a weakness and try to identify talent that can fill that space. It’s tricky, though. Easy to make mistakes. Hard to fix them. And in the end, it is the people who are there, and their intelligence, interestingness and willingness to take one for the team that will make the site. That’s what’s unique and individual to every site.