The real reason why that one girl has more friends on FaceBook than you
http://mindyourdecisions.com/blog/2012/09/04/why-your-friends-have-more-friends-than-you-the-friendship-paradox/
Doing a little stalking on FaceBook might make you come to realize that many of your friends have a lot more friends than you do. Looking at my own page, I see that I have exactly 250 friends somehow, yet my own sister and cousin have well over 600 friends. This fact always made me wonder how my younger cousin and older sister have so many more friends than I do, despite the fact that I am on FaceBook a lot more often than they are. I could make up many excuses, such as how they both are from schools that were larger than mine or that they are girls, but thats far from what really is going on. In fact, the real reason why is the fact that we’re all friends with each other. It is not that it is just me being friends individually, they are both friends with me, which causes FaceBook to show that they share the common friend of me. The commonality between us means that they are likely to friend each other, which gives them a boost in friends, as well as a larger common friend pool to gain more friends from.
A more technical look at it that relates to the class discussions is to look at it with nodes.If I were to be a central node X, with other nodes A, B, C, D, and E branching off from me, it is very likely that I am very close with them. The Strong Triadic Closure Property then comes into effect and FaceBook tries to connect as many of the friends I have as possible by recommending the friends to each other. Once a few of the nodes that branch off from me are connected to each other, the Strong Triadic Closure Property takes into effect again, this time there may even be more friends in common, further prompting my friends to add either my own friends or the friends of the friends. As time progresses, it becomes natural for my own friends to gain more friends than me due to the friends that I introduced to them.