As goes Facebook, so goes the world of social media – perhaps not the whole world of social media, but certainly those companies intricately intertwined with Facebook, like Zynga, the creator of popular (at least for now) Facebook games like “Farmville,” “Hidden Chronicles,” and “Mafia Wars.” Zynga shares have declined steadily over the last few months as fewer Facebook users play games through the social media platform. This week has been particularly unkind to Zynga, whose share price dropped 10 percent on Tuesday alone. What’s wrong with Zynga? Are Zynga shares not worth what they once were? Will Zynga shares continue to decline in value?