Could the stickiness of social sites such as Digg, Facebook or YouTube be explained by the notion that they function as hidden games?

The Read/WriteWeb blog points to an ebook by C. Weng on this very idea. In The Web: Hidden Games, available for free on Lulu, Weng argues that:

Officially, they are social networks, news aggregators, etc. and not designed as game sites like Second Life is. However, these sites contain all factors of a game. They are not only useful, but also entertaining.

This is an interesting take on the idea of social media and there is a ring of truth about it. After all, contributes to Digg will try to get their picks onto the front page and there are strategies to succeed at this.

Could journalists apply these ideas to news as a way of encouraging people to take a more active interest in the world around them?