Half year rankings for recochoku are out.
Top artists (download (single) category):
1. AKB48
2. Kana Nishino
3. EXILE
...
8. Koda Kumi
...
13. Lady Gaga
14. Ayumi Hamasaki
...
17. TVXQ
http://recochoku.jp/recochoku_rankin...st_single.html
Top artists (Chaku Uta):
1. EXILE
2. Kana Nishino
3. AKB48
...
8. Lady Gaga
...
10. TVXQ
...
13. Koda Kumi
...
22. Ayumi Hamasaki
http://recochoku.jp/recochoku_rankin...rtist_uta.html
It's pretty good for her!
I put some other artists up for comparison.
Namie Amuro is a bit behind, but she didn't release much.
For explanation:
Download (single) is the former Chaku Uta full category, so full songs download.
The normal Chaku Uta is just parts of the songs as ringtone for mobile phones.