1. Justin Bieber

2. Conor Maynard

3. Greyson Chance

4. Karmin

5. Soulja Boy

6. Arnel Pineda

7. Cody Simpson

8. Darren Criss

9. Charice

10. Bo Burnham

11. Lucas Cruikshank

12. Michelle Phan

Posting videos online led these people to fame and fortune. Catch the next generation of YouTube celebs in BlackBerry UK's LevelUp series.
YouTube Channel: kidrauhl
First upload: January 19, 2007
Mainstream success: A #1 album and three top 10 singles
Most popular video: A cover of Chris Brown's "With You" that has nearly 45 million views
YouTube channel: skillzaisherebooya
First upload: December 1, 2008
Mainstream success: A #1, BPA-certified silver album and MTV's Brand New for 2012 award
Most popular video: His cover of Chris Brown's "Next To You" with 12.5 million views
YouTube channel: greyson97
First upload: April 28, 2010
Mainstream success: Two studio albums on Ellen DeGeneres' record label and an appearance on the TV show Raising Hope
Most popular video: A cover of Lady Gaga's "Paparazzi" for his sixth-grade talent fair with 51 million views
YouTube channel: karmincovers
First upload: August 25, 2010
Mainstream success: A record deal and #1 single, "Brokenhearted"
Most popular video: A cover of Chris Brown's "Look At Me Now" with over 85 million views
YouTube channel: SouljaBoy
First upload: March 15, 2006
Mainstream success: A #2 single and a Grammy nomination
Most popular video: The music video for "Marco Polo," his song with Bow Wow, with 20 million views
YouTube channel: zoobandrocks
First upload: July 11, 2007
Mainstream success: He's the lead singer of Journey
Most popular video: A cover of Journey's "Open Arms" with 652,000 views
YouTube channel: CodySimpsonMusic
First upload: November 1, 2008
Mainstream success: Two studio albums, multiple appearances on Disney Channel shows
Most popular video: The music video for his single "All Day"
YouTube channel: StarKidPotter, which he founded with his theatre troop from the University of Michigan
First upload: June 19, 2009
Mainstream success: A recurring role on Glee
Most popular video: Act 1, Scene 1 from A Very Potter Musical
YouTube channel: Charice
First upload: March 19, 2009
Mainstream success: A guest spot on Glee, judge on the Philippine version of The X Factor
Most popular video: The music video for her single "Pyramid" which has just under 40 million views
YouTube channel: BoBurnham
First upload: December 21, 2006
Mainstream success: A Comedy Central special and a show on MTV (RIP Zach Stone, gone too soon)
Most popular video: His original rap "i'm bo yo" with 20 million views
YouTube channel: fred
First upload: October 30, 2006 (posted on Lucas' original, deleted account; Reposted to "fred" in 2008)
Mainstream success: Three Fred movies and a Fred TV show
Most popular video: A collaboration with The Annoying Orange that has 59 million views
YouTube channel: MichellePhan (formerly RiceBunny)
First uploaded: May 20, 2007
Mainstream success: A makeup line and spokeswoman deal with Lancôme
Most popular video: A tutorial for Barbie makeup with 47 million views