In other words, people can be persuaded to connect to networks, not only by the benefits of joining, but by the cost of not doing so.This may go some way to explain why so many people now have mobile phones or Facebook profiles: rather than being convinced of the benefits of signing up, people perhaps feel that by not doing so they are being 'left behind'.The phrase 'the whole is greater than the sum of its parts' is a good way of describing how networking works.

Gatekeepers and echo-chambers The rise of digital networks has had a transformative effect on the diffusion of messages across the world, a phenomenon that has been further enhanced with the advent of online social networking.

Whereas previously mass media companies and government institutions had a near monopoly over global message distribution, digital networks offered a way of bypassing the gatekeepers and communicating directly across the globe.

Roughly a third of the world's population are now connected to the internet.[1] At least for those who are online, this has had a profound effect on how people communicate and interact.

As the digital world has grown in significance, its societal influence has been studied and debated extensively, in particular the recent explosive rise in online social networking.

The network effect There are various definitions of 'network' but what they all share is their emphasis on the interconnected nature of networks.

Social networks are the theoretical constructs used to study the relationships between individuals or groups, where a social structure is built up from the various interactions between these 'actors'.

With people spending ever more time interacting online and only creating superficial connections with others, are 'real world' relationships being devalued, leading to increased social isolation?

And what of the effects in the political sphere - is social networking a powerful new tool for change or another way of reinforcing political hegemony?

More general theories and analysis of the internet and social media are also becoming more widespread, with 2012 seeing a number of conferences focusing on critical approaches to new social media, such as Unlike Us and the 4th ICTs and Society-Conference in Uppsala.

This article is not a comprehensive review of all this emerging analysis but covers some of the main issues and suggests resources to find more information.

That is not to say that traditional mass media institutions have entirely lost their grip.