The Society for Creative Anachronism started as a backyard graduation party for a medieval studies student and grew to 32,000 members as of 2008. Does anyone have any insight into how that happened? Of particular interest would be any intersection between the SCA's mode of growth and the usual modes of growth of religions (keeping in mind that not every intersection would be worth incorporating into a strategy for raising the sanity waterline by spreading LW-style ideas and approaches).
On May 1st on his blog he solicited feedback on an LW post in progress, so I expect he'll be around here sooner rather than later.