Tom Sander on Meetup, based on a research study undertaken this summer in a bunch of US cities: casual dating form of associationism - it's not a lifelong decision.

Study overturns stereotypes - not a young person phenomenon, was attracting well-educated, not newcomers, was not always strangers meeting strangers.

Do people stick? No, found low stickiness. Even when people were positive, half or two thirds might not come back. There is a lot of turnover, even with well established meetups. But there is social capital success: on average, 30% of the people do something outside the meetup with people they met there. 30% found new friends, 23% found 2 or more.

Strongly left-leaning: 10-15 times more opposed to Bush than in favor of him.

Turns out that leader-run meetups develop less social capital than the looser, ad hoc model: when the meetups focus more diligently on the business at hand, people develop fewer friendships, do less collectively outside th emeetings, and are less likely to come back.

Reprises the observation of Lee Bryant that when you move to bottom-up, everything needs to be bottom-up or things don't hold together.