Reasons for success
The success of the videos was in part attributed to the anticipation of the breakout moment and short length, making them very accessible to watch.
The Washington Post explained the meme's instant virality by referring to the jump cuts, hypnotic beat, quick setups and half minute routines.
The Harlem Shake is technically very easy for fans to reproduce, as it consists of a single locked camera shot and one jump cut. Nonetheless, the simplicity of the concept allows fans considerable scope in creating their own distinctive variant and making their mark, while retaining the basic elements. In its simplest form, it could be made with two people; a more sophisticated version might even involve a crowded stadium. Moreover, there is a level playing field for celebrities and fans alike, with no guarantee of success for either group. There is a strong vein of humour running through each video that is not dependent on language, further increasing its potential to spread virally.
source: wikipedia
