&gt; I wonder what the science is behind creating a successful, sustainable meetup.<p>I&#x27;ve been running meetups since ~2005&#x2F;6, co-founded a few, and currently run the AustinAPI meetup.<p>I&#x27;ve found that the single most important thing is having something of value. Education and relationships are the best with food and swag far behind. People want to know that they&#x27;ll go and either a) learn something or b) enjoy the other people, everything else should support those.<p>Immediately after that is consistency. If you have a given night of the month, location, and theme, stick to it. It will help the &quot;regulars&quot; know when, where, and how to find you. If you shuffle around the night or location, you&#x27;ll inevitably run into &quot;well, I was there on Tuesday, where was everyone!?&quot; (And notice that harms the relationship point above.)<p>After that, I try to nudge the group members occasionally. If there&#x27;s a group discussion list&#x2F;forum, share a relevant article once a week. If there&#x27;s a group twitter account, retweet that article or <i>relevant</i> events. When a member writes a blog post or does a presentation - in your group or elsewhere - celebrate them.