As you will have surely heard, Facebook recently acquired its 200 millionth user. It has achieved this in under five years, doubling in size in the last 8 months alone.
This has produced a lot of commentary. Since there is so much data surrounding people’s interactions with Facebook, it can be examined in all sorts of social studies.
One in particular caught my eye last week. The New York Times article had a sidebar produced by Facebook’s analysts, which is a wonderful piece of data visualization.
There are two parts. The first shows the global expansion, in a series of step changes precipitated by changes in the rules of who could join. It plots this against the average age distribution of the members. Facebook famously started at Harvard in February 2004 and quickly expanded to other universities, and you can see that initially all the members are 18-24 in the first graph. In 2005, it expanded to include most American colleges and high schools. In February 2006 it allowed anyone to join, and the age profile increased. By February 2007, it had reached 50 million members. By February 2008 Facebook is translated into more than 40 languages. Growth is fastest among those over 35.
For me, the second set of diagrams is the most fascinating. This is a real life example of what I’ve been calling ‘The Ecosystem of Influence’. It illustrates the Facebook network of one employee. The friends are dots, and the interactions are lines between the dots. It looks like an airline route map.
The point of the diagrams is that this individual has four networks of different sizes, defined by different levels of social intimacy. He has 178 friends in total. But he reads the postings of a much smaller group, and sends messages to a much smaller group yet again (“one way pings”). And of these only some reply. Without counting the lines, this looks like maybe 15