Kevin Winter, Getty Images
Justin Bieber appears onstage at his Comedy Central roast in March.
There are YouTube stars and then there are YouTube stars who made it out of the online world and in the corporeal-and-commercial world.
As the video-sharing website YouTube celebrates its 10th anniversary, take a look at some of the entertainers who now seem ubiquitous in the wider pop-culture but got their start from videos on that little black box popping up on a zillion computer screens.
Justin Bieber
He was a mop-top pre-teen Canadian who posted his first homemade videos on YouTube in 2007, when he was just 12. With his angelic demeanor and pretty-boy looks, Bieber went viral. One of his first videos, So Sick by Ne-Yo, has 7.5 million hits by now.
After he moved to America, Bieber signed recording contracts, started releasing albums that went multi-platinum, toured the world to ecstatic teenage acclaim, collected awards, 62 million Twitter followers, and millions upon millions of dollars.
His 2010 video of his greatest hit,Baby, with Ludacris, has got 1.1 billion hits. And counting.
Psy
Who? His real name is Park Jae-sang but few outside of South Korea had ever heard of the singer/songwriter/producer/rapper. Until Gangnam Style in 2012.
What was he singing? Who knows — it was in Korean. But the beat was catchy and his riding-a-horse dance moves made the video irresistible — so much so that it has been viewed more than 2.3 billion times.
That makes it YouTube's first video to exceed 1 billion views and the first to exceeed 2 billion views. It's the most watched YouTube video ever (after it passed Bieber's Baby in November 2012) and the most liked.