Justin Bieber is one of the biggest pop stars of all time -- and he’s not even 20 years old! He got his start in music by posting videos of himself performing on YouTube, and he now has over 3.1 billion views. In 2012, he sold out 2 shows in Madison Square Garden in just 30 seconds and his entire US and North American tour within one hour. He’s sold 15 million albums and grossed $150 million on 157 tour dates across two dozen countries. His “Boyfriend” video generated 8 million views in its first 24 hours and has built up to over 86 million views to date. He is one of Ellen’s favorite guests and has been on “The Ellen Show” twelve times in the past three years.