I want to know the answer to the following question:
It was confirmed by IFPI that Madonna officially sold how many albums worldwide?
All the background I'm provided with is that "Madonna embarked on the Confessions Tour in May 2006, which had a global audience of 1.2 million and grossed over $193.7 million, becoming the highest-grossing tour to that date for a female artist.". Is that enough to answer the question?