Sure, the concept of a social network wasn't novel, but Zuckerberg had some insights that led to FB becoming the dominant network within a few years - for examp

Sure, the concept of a social network wasn't novel, but Zuckerberg had some insights that led to FB becoming the dominant network within a few years - for example incubating inside US colleges to gain traction among younger demographics through word of mouth, building an ecosystem around games and apps, creating a social graph based on real identities and relationships that yielded lucrative marketing data, and so on.