Felix Kjellberg, a Swedish YouTuber, is the world's most popular Internet celebrity who earns almost $4 million yearly through ad sales.

According to his profile in The Wall Street Journal, most of his earnings are straight profit which comes from more than 27 million subscribers on his YouTube channel.

Kjellberg, 24, known as PewDiePie, created his first channel five years ago. In December 2012, he signed a deal with online video content creator Maker Studios, which sold itself to the media giant Walt Disney in a deal in March worth nearly $1 billion.

The Swedish YouTuber is popular in posting funny videos which are the basic video game reviews. But it has the "Let's Play"-style programs where he plays a title and narrates his experience to the viewer.

He said his videos are encouraging developers to create games that are not only fun to play but would also enjoy watching. Kjellberg added, "It's cool to have this kind of influence, but at the same time it's kind of scary".

For the past two weeks, Kjellberg posted more than two dozen videos featuring games like "Among The Sleep" and "Next Car Game," which have managed to attract more than 2 million views.

His most popular video, "A Funny Montage," has gotten more than 51 million views since it was posted on June 4 last year.

In the previous year, the PewDiePie channel rose as the most watched on Google's online video service, taking over the sensational Internet programs like "One Direction" and "Miley Cyrus."

Before Kjellberg reached his level of popularity, he went to college in Gothenburg, Sweden and uploaded videos during his spare time. Then he dropped out of school and started selling hotdogs for a living.

The original name of the YouTube account was PewDie, which was an arrangement of the "pew" sound of a laser gun and "die" for death. When he lost his account password and created a new name, he decided to add "Pie" at the end of his original name.