Given some stereotypes of social media users (I just told a reporter from the German Press Agency that the Star Trek ones are true :) ) this group is not a bunch of people who prefer to stare at their iPhones instead of making eye contact. In fact, their most defining characteristic is the ability to have a great conversation. They're interesting and interested. Their hyper sharing online translates into hyper helpfulness offline. And given the friendly nature of the technical social channels, there's much more of a "we're all in this together" feel than you would find at a space-focused industry conference. So this tweetup, far from comprised of 100 geeks who can fill out an online form really fast, is a precision filter for knowledgeable, passionate and uber-information sharing members of the new media.
And since EVERY company works in a sector where people are passionate about its ideas, ANY company can enjoy similar success with atweetup. No space shuttle required.