Another big round in the social apps space, as Social Gaming Network has raised a $15 million first round from Greylock Partners, the Founders Fund, Columbia Partners, and Novak Biddle Venture Partners. Among its game titles: Warbook, Jetman, and Text Twirl. All the bigs in this space are building up war chests. Competitors Zynga raised $10 million in its first round, while Slide added $50 million last year. It’s been rumored that RockYou has gone out for a big round as well. Other, smaller competitors in the space have raised more modest rounds. Why so much money being tossed about? Some of it is probably flavor-of-the-month reasoning, but for those that have broken out, the assumption is that their growth is still in the early stages. And there’s already signs of an anticipated consolidation: last month SGN itself acquired smaller developer Esgut. Release.

Wagner James Au at GigaOM interviewed CEO Shervin Pishevar about the economics of the business: “While Social Gaming Network’s low-graphics games aren’t likely to be confused with a next-gen title, he told me, they’re successful enough. ‘Small is the new big, right?’ Games like Warbook can be made with a low budget, he noted. “Even having a 100,000 daily active users is good revenue.” (At peak usage with a sponsorship deal, he said, Warbook was making $100K a month.) ‘We’re much more about engagement and retentions than virality,’ Pishevar told me.”

• Social Gaming Network Acquires Facebook App Developer Esgut
• Social Casual Gamer Zynga Raises $10 Million First Round