The format being "desktop web games played inside Facebook." That format has a number of consequences in terms of the kind of genres, features, production value

The format being "desktop web games played inside Facebook." That format has a number of consequences in terms of the kind of genres, features, production values, technology, etc that turn out to work in practice. In addition to that, it's certainly true that Zynga as an organization with certain processes, culture and etc. may have proven unable to innovate. Their lackluster track record in the much more fertile ground of mobile suggests this is the case.