Simple. The Fame with re-release The Fame Monster sold over 13 million copies worldwide.

i doubt. i rarely even see her promote. after "born this way"...21 will be over

At this rate, selling more than 100k a week, it's possible.

It's possible. It's sold so much already and still #1. It hasn't even had the benefit of a holiday period yet.

You're delusional to think 21 will stop selling due to Born This Way being released. GaGa and Adele do not even appeal to the same audience, and the fact that "Rolling in the Deep" mollywhopped "Judas" on the charts and peaked after "Born This Way" peaked when it was released before proves that Adele could very well hold her own.

Anyway, in the U.S., it's most definitely possible. Worldwide? I'm not sure. It's certainly possible with a re-release.

Without a re-release, there is zero chance. I do not see Adele doing a re-release for 21.