Did you get a feel of the education/income/social status of the group you saw? I wonder if they try to recruit a certain type of person.
I learned that some of the people there were really high-profile, but I don't know the percentages. On the other hand, some others were perfectly ordinary folk, so if there is a preference it's not exclusive.
For example I remember that one guy (they said) had a company selling electronics, and gave others lots of expensive presents ("presents"?) like Alienware gaming hardware etc.
I was invited by a stranger I met on a plane and actually went to a meeting of Raëlians (known in some LW circles as "the flying saucer cult") in 沖縄, Japan. It was right next to Claude Vorilhon's home, and he came himself for the "ceremony" (?) dressed in a theatrical space-y white uniform, complete with a Jewish-style white cap on his head. When saying his "sermon" (?) he spoke in English and his words were translated into Japanese for the benefit of those who didn't understand. And yes, it's true he talked with me briefly and then hugged me (I understand he does this with all newcomers, and it felt 100% fake to me). I then went on to eat lunch in an 居酒屋 with a group of around 15 members, who were all really friendly and pleasant people. I was actually treated to lunch by them, and afterwards someone gave me a ~20 minute ride to the town I wanted to be in, despite knowing they won't see me ever again.
If you have ever wondered how it is possible that a flying saucer cult has more members than EA, now it's time to learn something.
Note: I hope it's clear that I do not endorse creating cults, nor do I proclaim the EA community's inferiority. It hasn't even crossed my mind when I wrote the above line that any LW'er would take it as a stab they need to defend against. I'm merely pointing to the fact that we can learn from anything, whether it's good or bad, and encouraging a fresh discussion on this after I gathered some new data.
Let's do this as a Q&A session (I'm at work now so I can't write a long post).
Please ask questions in comments.