Justin sold 4 million albums in one year

Having sold out Madison Square Garden the other night, Justin Bieber is celebrating another milestone -- he sold 4 million albums worldwide in less than a year. Bieber has now sold 3.2 million copies of his "My World" (released last November) and "My World 2.0" (March) in the US, plus 7.7 million songs digitally downloaded, according to Nielsen SoundScan.

His manager, Scooter Braun, told us: