Last month we reported that video game publishing giant Electronic Arts was planning to purchase a social games company, and today it was confirmed that EA has purchased Playfish — the makers of popular Facebook games like Pet Society, Crazy Planets, Geo Challenge and Restaurant City — for approximately $275 million in cash, $25 million in stocks, and further variable cash bonuses of up to $100 million dependent on achieving certain performance-based milestones over the next two years.

According to Gamasutra, Playfish will now operative as part of Electronic Arts Interactive, or EAi, the division of EA that focuses on Web, mobile and wireless business and also includes EA Mobile and Pogo.

“The industry is undergoing dramatic transformation and joining EA is the ideal opportunity for us to push forward our goals to lead in the social entertainment evolution on a faster and much larger scale,” said Kristian Segerstrale, CEO and Co-founder of Playfish, in a press statement released by Playfish earlier today. “EAi’s vision and entrepreneurial culture are consistent with our own, and together, we are in position to be the company that defines new and innovative connected experiences that will change the way people play games.”

“Social gaming, with its emphasis on friends and community, is seeing tremendous growth and this is the right time to invest to strengthen our participation in this space,” added Barry Cottle, said Senior Vice President and General Manager of EA Interactive. “EAi has been successfully leading the charge for EA, and with the addition of proven expertise from Playfish, their broad consumer base and strong game brands, we’re moving ahead aggressively in our plans to lead in the category of cross-platform social entertainment.”

For more information on the acquisition, read Gamasutra’s interview with Playfish CEO Kristian Segerstrale and EAi’s Barry Cottle and Games.com’s interview with Playfish COO Sebastien de Halleux.