Analysis of Clark Meetupers

While tracking down some Meetup data, I found this Bentley College survey from January that analyzes Wesley Clark's supporters and their use of Meetup. Beyond the Clark demographics, it says, "Clark attendees were more likely than Dean attendees to find out about the December Meetup through Internet sources. Just over 20% of both groups mentioned an invitation from someone they knew. In October, Dean attendees also reported more personal invitations to their first Meetup." Any other research yet on who uses Meetup politically and how?