Foursquare, fourth dimension of social networking
http://www.nytimes.com/2009/10/19/technology/internet/19foursquare.html
Twitter and Facebook ask users to answer the question: What are you doing right now? This may be the most fundamental question that drives the social network to be an on-going system. This question is not only imposed in these two social network services, but in many others including Foursquare and Loopt. However, Foursquare came up with an innovative means for people to interact with each other; while facebook and twitter focused on verbal communication, Foursquare mainly appealed with its check-in system that incorporates elements of gaming and social competition.
Foursquare has introduced a whole different dimension of social networking. It motivates the users to use the program by awarding them with virtual awards and via this process people naturally connect with each other in a more sensible way. This is a good example of Triadic Closure in real life scale. Connection between people branches out as network accepts more and more people that share something common. This may be the most basic theorem behind the functioning of every social network service, but Foursquare enables interaction that is beyond other services. It is as if people are put together within a square, perhaps physically rather than virtually.