If you want to make a video go viral - get billions of views and prompt thousands of spin-off versions - then you'd do well to look at what happened to Gangnam Style and The Harlem Shake . Using 'content tracking technology', this data visualisation compares how the two phenomena exploded on and continued to live in Twitter.On the right, Gangnam Style, which owes a large part of its online success to tweets from Katy Perry and Britney Spears - this is known as the top-down 'rise' model of virality. Fewer large circles for the cluster on the left show that a far greater number of lesser-known users made The Harlem Shake the sensation it became - the bottom-up 'burst' model.• Who made this visualisation? Face • See more visualisations in this series