If you haven't heard "Kolaveri Di", you are supposed to be out of sync with the world. The Tamil song with nonsensical lyrics that came out just eight days ago has already notched up up 18, 50, 000 hits on YouTube and its fan following includes the young and the old, the commoner and the celebrity.

Seldom has any song created such a craze "with almost 1.8 M hits on YouTube and with over 8.2 M links shared on Facebook in less than a week", a Sony Music statement said.

"Such is the effect of the song that strangely my two-and-a-half-month-old son slept listening to 'Kolaveri Di', " said Janice Goveas, a professionak said.

Ths song is sung by Tamil star Dhanush for his film "3", which is directed by his wife Aishwayra Dhanush.

Not only down south, the craze for the song has caused an all-India frenzy. National TV channels have carried stories about the song's popularity.

"Kolaveri di...definitely the sleeper song blockbuster of the year!!! Rock on Dhanush!!!, " tweeted Bollywood filmmaker Karan Johar.

Bollywood megastar Amitabh Bachchan tweeted: "Just heard #Kolaveri after much talk on it... it's so original and catchy...congrats Dhanush and Aishwarya (Rajni's daughter).. love"

The composer of the song, 18-year-old Anirudh, is unable to explain the phenomenon it has become, saying: "It's probably because of the funny, broken English and some amount of musicality, but I cannot really explain beyond a point."

G. Ravishankar, who is part opopular band Zinx led by Anirudh, said: "It is simple and catchy. It captures your imagination. It makes the youth dance and sing instantly."

The unprecedented success can also be attributed to the clever marketing plan of Sony Music Entertainment India, which has released the single track album.

"We wanted this song to go viral on cyberspace. We marketed aggressively to make the song a national rage, by posting it on Tamil, Hindi and international Facebook pages, apart from releasing it on YouTube. The video accompanying the song was recorded at 2 a.m., and edited on the day of the release, " says Ashok Parwani, associate director, Sony Music Entertainment India.

"Getting 2 million hits on YouTube is a good sign, but our aim is to reach 15 million", he added.

However, Tamil writer Kadarkarai begs to differ.

"It is a song that lacks in musical finesse and depth. Fine music is created and enjoyed by mature minds. It is predominantly the adolescent minds that make this kind of superfluous songs a rage. Those minds do not have such memories and hence this popularity. I hope they would grow up soon and enjoy fine music soon" he said.

Criticism notwithstanding, the song's popularity is growing and it is being broadcast on Hindi FM channels. It will also be played on all 32 Radio Mirchi stations and 43 Big FM stations, adding a viewership of more than 300, 000 to its YouTube link everyday.

The publicity can help Dhanush, who plans to direct a Hindi film next year.

The song will also has the distinction of being the first Tamil song to be premiered on a national music channel, MTV, on Thursday.

Dhanush has teamed up with Shruti Haasan in the film.