to be honest, even if something is promoted a lot, it still doesn't mean it's going to sell well. Koi no groovyx2 was promoted A LOT here. A LOT. It was played in shibuya constantly, and trains were plastered with the GAP ads and the tv's even had the making of and interviews playing--yet it sold poorly. And also, Japanese people still like upbeat songs, and Yuna tends to rely on ballad heavy things.
The problem is that she isn't striking a cord with Japanese people.
And from what people said about Sony, Miliyah Kato has never really been heavily promoted, she usually has like one performance per new thing, and she's selling well. I think her new album will get #1 if there isn't any big competition. She's becoming a style icon amongst Japanese youth and her lyrics are really meaningful.
A lot of people here don't speak Japanese and therefore only listen to Yuna for her personality and the music of her songs. The lyrics meaning's aren't the most important things to you (generally speaking) so it's easy to say that this album is amazing or something like that.
I'm not trying to say that popularity in general doesn't account for a lot of sales, but I mean, there are a lot of other aspects.
