^ But as I said, it's really only been the last few years I think that her albums have gotten released overseas. I doubt there are millions of people that after that went out and bought her whole back catalog. You have to keep in mind that Japan is the second largest music industry in the world in terms of sales behind the USA and the other asian countries traditionally have not been anywhere close to that - though Korea's music industry has been picking up. To hit a million copies for an album or even close to that outside of Japan, as far as I have seen, is a very rare thing to do even for the top korean, top chinese artists etc in their own home country, let alone for a foreigner.
For example, the best selling album for Korea in all of 2007 sold a whopping 190,998 copies. And it wasn't Ayumi's album.