[Toniayu123]

I think she is aware of her sales but probably doesn't care about it anymore. I think low sales are in part due to bad/lack in promotion. In this industry almost everything is about promotion, and the way avex (or a third party, I don't know) handled it definitely is not the right one. I'm not talking about massive promotion in all media (which would help) but rather strategic one, and most importantly, Ayu image in Japan. I don't really know because I don't live there but it seems Ayu doesn't have a good one, while Namie (and sorry to bring the same discussion here again) does.
edit: and I consider Ayu's sales nowadays pretty good and stable, just not as HUGE as they used to be in the past. On the other hand, I love Ayu's image despite all the hate toward it.