Justin Bieber
Manager Scooter Braun discovered the Biebs in 2007 after he began posting homemade videos on YouTube of covers of popular hits, like Chris Brown's "With You." A random meeting with Usher led to an audition and an eventual recording contract. The rest is sweet history...
The Weeknd
Abel Tesfaye began posted YouTube videos of his music under his stage name in 2010. The clips quickly went viral and gained the attention of industry heavyweights like Drake, who posted some of them on his personal blog. He continued to expand his fanbase a year later by releasing three mixtapes. All the praise and critical acclaim ultimately landed him a record deal.
Kate Upton
It's almost hard to believe Kate Upton ever had trouble getting noticed, but at the beginning of her career, the supermodel was struggling to make it big until a friend posted a video on YouTube of her doing the "dougie" at a basketball game in April 2011. It soon went viral and she gained almost 200,000 Twitter followers and a whole lot of attention.
Shawn Mendes
It only took six seconds for the music industry to realize Mendes was a star. When the "Stitches" singer shared a Vine video of himself covering Justin Bieber's "As Long As You Love Me," it immediately went viral and he amassed thousands of followers. Mendes was eventually contacted by numerous record labels hoping to sign him. He went with Island Records and debuted his first EP in 2014.
Darren Criss
After the Glee star founded a YouTube channel called Team StarKid with a few of his theater friends from the University of Michigan, he went on to become a big star, most famously known for his role on the Fox musical show.
Austin Mahone
The "Dirty Work" singer kicked off his career on YouTube by posting videos with a friend in 2010. After gaining a loyal following, he signed a record deal in 2011.
Colbie Caillat
The singer-songwriter first gained a following on MySpace, drawing thousands and thousands views of her performances each week on her profile in 2008. She has since gone on to win Grammys and collaborate with Taylor Swift and Jason Mraz.
5 Seconds of Summer
The boy band took a page out of fellow Aussie Cody Simpson's book and started posting videos of covers on YouTube. Their following helped them nab an opening slot on One Direction's tour and the group signed a record deal soon after.
Sophia Grace & Rosie
Sophia Grace and her cousin Rosie have been featured several times on The Ellen Degeneres Show. The adorable duo, who hails from England, started creating buzz after their performance of Nicki Minaj's "Super Bass" took YouTube by storm in 2011.
Cody Simpson
The Aussie musician jumpstarted his career on YouTube with covers of Jason Mraz, Justin Timberlake and The Jackson 5. At 12, he caught the attention of producer Shawn Campbell, who helped him sign his first record deal.
Carly Rae Jepsen
Similar to Justin Bieber, manager Scooter Braun used YouTube to find the Canadian singer-songwriter. He definitely liked what he saw and heard because he swiftly signed her to his label, Schoolboy Records.
Sean Kingston
The "Beautiful Girls" singer was discovered online and signed a record deal in 2007.
Soulja Boy
The rapper created YouTube and MySpace accounts to promote what would eventually become his first hit, "Crank That (Soulja Boy)." That smart move led to a record deal with Interscope Records in 2007 and a Grammy nomination for Best Rap Song in 2008.
Charice
The Filipino singer garnered international attention after multiple videos of her powerful cover performances found their way onto YouTube. She soon made appearances on The Ellen Degeneres Show and Oprah and released her own albums. Charice also joined the cast of Glee in 2010.
Karmin
After achieving millions of views on YouTube for covers of Chris Brown and Nicki Minaj, the duo signed a record deal in 2011 and released their own hits, including "Acapella" and "Brokenhearted."
Greyson Chance
When a video of Chance singing Lady Gaga's "Paparazzi" went viral, he was invited to appear on The Ellen Degeneres Show and subsequently signed a record deal.