What do a Japanese high school student, a former Brazillian soccer player and a college student in Malaysia have in common? All three of them are known to be a 'Big Mouth,' which is a term for a person who helps to spread the word. In this case, they're spreading the word for K-Pop and its popularity worldwide. 

The most important medium for the expansion of K-Pop has been YouTube, Twitter and other Social Media websites. The people who maintain the content on these websites are common people and fans around the world. It's not a big network or a management company but regular fans who are instrumental in spreading the word. 

Hallyu is a real phenomenon but until now, people hadn't really figured out what drives the spread of Korean culture and its popularity. A Research Center for Cyber Traffic at Youngnam University has been analyzing tweets since last November to see who is actually influential in introducing other people around the world to K-Pop. They looked at tweets from the Americas, Asia and Europe, spanning the entire world. 

The results showed that there were specific people, or "Big Mouths", who were clearly influential. Most of them started out as fans of the Hallyu movement and eventually became a 'hub' for information on K-Pop. 

In Japan, a user called 'kpop_lov' was the most influential in talking about K-Pop issues. According to her Twitter profile, she is a 2nd year high school student in Fukuoka. She fits perfectly into the 10-20 year old female demographic that Hallyu is so popular amongst and she eventually became a very knowledgeable amateur source of information on K-Pop in Japan.

In Southeast Asia, a new blog that formed in 2009 called 'dkpopnews.net' is the most influential. They record a daily hit average of 280,000 and because they operate in English, they draw readers from the Philippines, Singapore, USA and Australia. The webmaster Casey Ui is a Malaysian college student, who owns the Twitter account 'dailykpopnews.'

In Europe, the main hubs are located in Germany, France and the UK and out of those countries, France and Germany have been the most prolific in terms of tweets about K-Pop. In Germany, the first Korean star was model Nela Lee and the Twitter account 'nelapanghylee' has been the most influential in terms of tweets about Korean culture. In France, the internet radio station 'K-Pop FM' and its technician Jonathan Grey has been the biggest information hub on Twitter.

Interestingly, there have been regional differences. In North America, the most prolific K-Pop supporters haven't been individuals but rather bigger entities, like the hub 'dramafever.' This isn't just one person but it's a website that services in Korean dramas and music videos, and it's one of famous Hallyu informational websites in the US. 

After having conducted the research, Professor Park Han Woo said, "If you analyze the Twitter network, you can see that the Hallyu phenomenon mainly begins with amateur media sources and just regular fans. If we keep analyzing this in detail we can probably continue this trend."