As of June 2011, the album has sold an estimated 50 million copies worldwide, making it tied for second highest selling album of all time, the highest-selling album by a band, the best-selling hard rock album of all-time, and the best-selling album ever released by an Australian musical act. On 13 December 2007, the RIAA certified it 22x multi-platinum, recognizing sales of 22 million in the US, making it the sixth highest selling album in the U.S. (fourth-highest at the time).