<i>I wonder what the science is behind creating a successful, sustainable meetup.</i><p>In my experience it comes down to the organizers actually caring and putting in a TON of effort. A bit like organizing a successful conference really. It&#x27;s absolutely exhausting but every meetup I know that works well has someone (or multiple people) slogging their guts out and draining their emotional energy on connecting people, finding new attendees&#x2F;speakers, and keeping it going.<p>When a meetup turns into a mere &quot;get X people in a room and do little else&quot; it starts to tail off and people split off into cliques and eventually meetups die (but I did make two great friends recently out of such a situation).