Kevin: I interviewed Playfish CEO Kristian Segerstrale earlier this summer for a feature for the Guardian. He understands the social aspects and economics of the gaming business more than most people I've met. He not only built a successful company in two years, but with the sale to gaming powerhouse EA for $400m, the company is a textbook case in how to quickly build a company. From a social standpoint, he says: "It's all about audience engagement. You create a product, and you nurture it and you nurture it and nurture it."