It felt like the biggest product launch party in the history of DC tech. A line snaked down 15th Street, and 1,500 or so people crammed into startup campus, 1776, to celebrate SocialRadar.

The startup launched its iPhone app a few weeks ago but officially debuted the social networking tool last night. Many were using the app during the party to see who else from their social networks were present. That’s how we tracked founder Michael Chasen, whose party featured lots of drinks, food, dancing, former Blackboard colleagues, and lots of others from the tech economy.

We caught up with Cooley partner Mike Lincoln and Urban Venture CEO and Nanobird COO Ben Wan. Mike says the launch proves it’s a great time in the startup tech market. It’s also good for the region to see people like Michael start new ventures after successful exits, Mike adds. (Blackboard was sold in 2011 to Providence Equity Partners for $1.7B.)

The party brought out LogiAnalytics biz dev VP Kevin Greene and Cooley biz dev VP Katherine Ferguson. Kevin joined the company nearly a year ago but still does some advising for his former employer, Valhalla Partners. Knowing there would be over 1,500 smart people in the room, Kevin came armed with a sheet of paper that described six open positions at the McLean, Va., firm.

A launch party isn’t complete without cotton candy. (We also spotted popcorn, donuts, and cupcakes.) Surrounding the cotton candy dispenser: SocialGrinderDC’s Dave Haft, Good Fight Media’s Nathan Golon, ImpactHubDC’s Alex Denny, and Good Fight’s Chris Keener.