Do you remember Friendster? I do – it was the first social media site that I was active on, before MySpace and Facebook. Friendster was widely embraced and grew quickly – but, what happened? Was the competition from MySpace and then Facebook just too much? Some researchers have conducted what they call a digital autopsy, and reveal their findings in this new paper.
David Garcia and fellow researchers at the Swiss Federal Institute of Technology in Zurich conducted the research. They say that when the costs (in this case time and energy spent on the site) outweigh the benefits, then the conditions are ripe for a mass exodus. If a user inactivates their profile, it is far more likely that one of his or friends will as well, which in turn could impact the second friend’s network, and so on. The researchers further explain that the topology of the network provides some resilience against this. This resilience is determined by the number of friends that individual users have, and the average number of connections for each user.
Let’s say a huge chunk of users only have 5 friends – that network is very likely to fail, because when a single person exits, it leaves somebody with only four friends. If one of those friends also leave, then it’s down to only two… the ripple effect sets in and a major collapse is going to happen. However, if a large percentage of users on the network have a higher volume of friends, one user leaving does not make as big an impact.
So the fraction of the network with a certain number of friends is a crucial indicator of the network’s vulnerability to the ripple effect.
Garcia and fellow researchers examined this fraction (they call it k-core distribution) for networks such as Friendster, Myspace and Facebook and the results are telling. “We ?nd that the di?erent online communities have di?erent k-core distributions,” they say.
It is the combination of a low cost-to-benefit ratio and a vulnerable k-core distribution that is fatal for social networks. In the months before the collapse of Friendster, the cost-to-benefit ratio dropped dramatically as a result of design changes and technical problems, so users fled quickly, the researchers say.
So in this digital autopsy, the cause of death was a drop in the cost-to-benefit ratio among users. “This measure can be seen as a precursor of the later collapse of the community,” they conclude. But a contributing factor was also the k-core distribution.
Ref: arxiv.org/abs/1302.6109: Social Resilience in Online Communities: The Autopsy of Friendster