According to the New York Times report, D.S.T. also plans to purchase stock from shareholders in addition to directly investing in Zynga, with the goal of further growing Zynga's estimated annual revenue of $250 million. While the immediate effect on Zynga's valuation has yet to be disclosed, the company had previously raised $39 million from other investors, meaning that this new set of deals more than quadruples the money obtained from previous investments.

The influx of cash from D.S.T. arrives in tandem with other recent undisclosed investments from New York hedge fund Tiger Global, Institutional Venture Partners, and the $300 million venture fund, Andreessen Horowitz.

A couple of unnamed experts in "Internet company finance" told the New York Times they believed that "...it would be reasonable for Zynga to command a valuation of two and a half to six times its annual revenue." That could put the value of the two-year-old Zynga at $1.5 billion; one industry insider believes the value could be as much as $3 billion."

It's not Digital Sky Technology's first plunge into the social gaming market, and the company believes that social games that include paid micro-transactions for virtual goods will continue to increase in popularity with Western audiences. Back in May, the firm had struck a similar investment deal with Facebook, effectively buying preferred shares at a premium and common stock at a lower valuation.

D.S.T.'s recent investments have also raised a few eyebrows due to the fact that Alisher Usmanov, a Russian billionaire who served six years for fraud and embezzlement in a Uzbek jail, owns 35% of the firm.

It's yet another development in the growing landscape of social gaming, illustrating increasing interest from big investors, and comes hot on the heels of Electronic Arts' recent $300 million purchase of rival social-game company Playfish, and Square Enix's recently expressed interest in the social gaming space.