The two models of virality is the first to look at, beginning with the Burst model. The burst model is bottom-up. The videos that spawn off of the original tend to be much more popular than the original. The videos that follow this model tend to be unclear as to the origin of the leadership video. Harlem shake is based off of this model, because it relied on the community relevance to spread. These tend to spread very quickly, but not endure.
On the other hand, there is Rise model. The original is always much stronger than the spin offs and is clear as to which video started it all. Rises tend to spread slower, but endure much longer because the meme has a focal point. This urges video makers to try and plan their model accordingly and decide which one they are planning on using. This is the type of model that Gangnam Style has.
The next thing to look at is the triggers. Virality is often triggered by surprise and comes on to the scene quickly. Cultural relevance is a must or else communities will simply not be interested. Communities drive the virality, not people influencing it. A meme also needs a focal point, something to sustain it with leadership and strong narrative. A meme also tends to go across the globe, so it needs a balance of local relevance, but still has an appeal all over the globe. When you log onto the World Wide Web, the lines between close and far grow pretty gray.
However, triggers are not consistent and tend to be in waves and spikes. Weak ties and communities sustain for a short while, but do not give scale in the short term. Celebrity endorsement may also seem like a help, but even though it may give a quick, huge burst, it tends to die out quickly in a matter of days, due to the decreasing share ability of the meme.
In the end, viral videos are part of a complex system that shouldn’t be taken lightly. Harlem Shake and Gangnam Style, although two very different videos, became two of the most used viral videos in marketing. They followed two different styles, with Harlem Shaking sharing more and lasting shorter and Gangnam Style Sharing less, but having a much more sustained popularity, mainly due to the celebrity and higher media coverage surrounding it.