Katy Perry disses Miley 's tongue , Miley bites back . Her fans have bought 72 million digital singles online . The singer has sold more than 100 million albums worldwide and is the best-selling female artist of all time. Recording Industry Association of America began awarding gold and platinum digital singles in '04 .
Her fans have bought 72 million digital singles online . The singer has sold more than 100 million albums worldwide and is the best-selling female artist of all time. Recording Industry Association of America began awarding gold and platinum digital singles in '04 .