Playfish scored big last week as Electronic Arts said it would buy the social gaming company for as much as $400 million. That’s a remarkable achievement for a company that is just a couple of years old. It’s a validation of the fast growth of the social gaming market and a tribute to Facebook’s growth as well. With original games like Pet Society and Restaurant City, Playfish has been able to garner 59 million monthly active users on Facebook, not to mention users on other social networks and the iPhone as well. We caught up with Kristian Segerstrale, co-founder and chief executive of Playfish in London, for an interview. Segerstrale’s co-founder, Sebastien DeHalleux, president of Playfish, is speaking at our upcoming DiscoveryBeat event on Dec. 8.