Things we perceive to be virally popular online are often not. Sometimes we fall victim to an illusion emerging from the nature of social networking that makes rare things seem common.
The nuts and bolts of pseudocelebrity thinkfluencing, explained:
Lerman and co have discovered a related paradox, which they call the majority illusion. This is the phenomenon in which an individual can observe a behavior or attribute in most of his or her friends, even though it is rare in the network as a whole.
They illustrate this illusion with a theoretical example: a set of 14 nodes linked up to form a small world network, just like a real social network (see picture above). They then color three of these nodes and count how many of the remaining nodes link to them in a single step. Two versions of this setup are shown above. In the left-hand example, the uncolored nodes see more than half of their neighbors as colored. In the right-hand example, this is not true for any of the uncolored nodes.
But here's the thing: the structure of the network is the same in both cases. The only thing that changes is the nodes that are colored. This is the majority illusion—the local impression that a specific attribute is common when the global truth is entirely different.
I have illustrated the effect above to demonstrate how just three examples of Sonic fan art in one's social network can make Facebook look like a dark, sticky corner of Deviantart for a whole day.