Hacker Angel Roy Rodenstein (founder of Going.com, sold to AOL) on Mixergy

Finding out about them was mostly my cofounder Rebecca, who's a social maven in her own right. But, once you attend a few you start to find out and get invited to a lot more, so it's not hard to sustain.

What we did when we got there was definitely something we tweaked and thought about. Obviously we mostly wanted to be very friendly and just let people know about us if they cared, no pushy sales pitches at all.

We - made cards - had a very 'normal' conversation with people, but asked what they do - that typically resulted in them asking us back, which was a natural segue into mentioning Going (HeyLetsGo at the time). Since we already were at a social event, and HLG was about finding more cool things to do, it was usually relevant to them. - we would them offer them an invite as we were in private beta at the time, often asking them to send us feedback - and we'd hand them a card with an invite code (we later made cards for some Ambassadors)

Not only did this help our early growth, we also found a lot of advocates, people who wanted to pitch in, and smart people with good feedback.

I do, and it's already used all the time (e.g. DailyCandy charges thousands of dollars for a Dedicated Email for a given city's email list). What we did was sort of roll our own campaign, trading the positive association with our unique event as well as a booth, signage etc. there for cash-free marketing for us.