Canadian recording artist Justin Bieber has released three studio albums, four compilation albums, one extended play, nineteen singles (including five as a featured artist), six promotional singles and twenty-four music videos. As of April 2012, Justin Bieber has sold eight million albums in the United States and over 15 million albums worldwide. At the age of thirteen, Bieber was discovered on YouTube and subsequently signed by R&B singer Usher to Raymond Braun Media Group (RBMG). Popular urban producers Tricky Stewart and The-Dream were enlisted for Bieber’s debut single, “One Time”, which peaked at number 12 in Canada and reached the top twenty in several other countries. Bieber’s debut extended play My World was released in November 2009; it debuted at number one in Canada and reached the top five in several other countries, including the United Kingdom and the United States. The EP also produced the successful follow-up single “One Less Lonely Girl”, as well as the promotional singles “Favorite Girl” and “Love Me”. Bieber’s full-length debut studio album, My World 2.0, was released in March 2010. The album was a commercial success, topping the charts in countries such as Australia, Canada and the United States. My World 2.0 received multi-platinum certifications from Music Canada (MC) and the Recording Industry Association of America (RIAA). The album was preceded by the release of its lead single, “Baby”, a collaboration with American rapper Ludacris. It became an international hit, reaching the top five in countries such as Canada, Australia and the United States. Follow-up singles such as “Somebody to Love” and “U Smile” also attained commercial success.