Why This Kolaveri Di by Dhanush. Check out this video shot during the recording of the song with the music composer Anirudh, Dhanush, Shruti Hassan, Aishwarya and Sound Engineer Sivakumar. This promotional video goes viral on internet. The video is uploaded on Nov 16, 2011 on Youtube. Just within 5 days it got 1 million plus views while it is a Tamil Song. Everyone listening and enjoying the song whether knows Tamil or not.
Getting 1 million views in 5 days is Exceptional, even for a mainstream Bollywood song it's very tough.
PS: Dhanush (the singer) is Rajnikanth's son-in-law, that might be reason.