Madonna has sold like 40M albums and singles more than Mariah worldwide (excluding, 'COADF').
There is no way Mariah would catch up to that in 5 years, not to mention Madonna will be adding millions more to the gap in sales between them, with 'COADF'.
Britney has TWO Diamond albums (10 million sold), while most of these don't.Britney will have a HUGE comeback. Emancipation will be a bug compared to the succes Britney's gonna get in 2007!
