Aren't the vast majority of Zynga's users coming from Facebook? If you go to Farmville.com, you need to login with Facebook Connect. I would have a different opinion if Zynga could survive without the Facebook interactions. However, their games rely on the network effect that Facebook brings... so they are very dependent upon the 'walled garden' of Facebook.
Now, this isn't the same type of garden as AOL in the day. It's more open, but make no mistake, Facebook controls the user, not Zynga. Because of this, Zynga has more risk than another web-based game company would be. At the same time though, Zynga has gained incredibly from the relationship.
But, if Zynga wants to keep the users coming, it needs to maintain that Facebook relationship.
Now, this isn't the same type of garden as AOL in the day. It's more open, but make no mistake, Facebook controls the user, not Zynga. Because of this, Zynga has more risk than another web-based game company would be. At the same time though, Zynga has gained incredibly from the relationship.
But, if Zynga wants to keep the users coming, it needs to maintain that Facebook relationship.