I'm really interested to see how Utada does with SINGLES COLLECTION VOL.2. Her popularity has faded and sales of This Is The One were low even when you include the fact it's an English album since Exodus sold over 1,100,000 in Japan.
Well it didn't do as well as Exodus because sales are obviously going down across the board. You can't compare a 2009 album with a 2004 album.
Exodus was advertised mildly in Japan, and This is The One was not advertised at all.
I can't refute the popularity point because this is going to happen with any artist that has been in the game that long. Look at Namie. I'm not saying she is doing bad, but are you going to tell me she is doing just as good as when she was at her first peak?
# Artist Single Sales
1 ARASHI Løve Rainbow 528,844
2 GLAY Precious 63,267
3 HO-KAGO TEA TIME Gohan wa Okazu / U&I 52,785
4 Girls' Generation GENIE 44,907
5 French Kiss Zutto Mae Kara 40,983
6 AKB48 Heavy Rotation 14,842
7 Hikawa Kiyoshi Nijiiro no Bayon 13,081
8 Otsuka Ai I ♥ ××× 10,322
9 10-FEET hammer ska 9,158
10 WaT 24/7 ~Mou Ichido~ 9,057
11 Hata Motohiro Metro Film 8,891
12 Kanjani8 LIFE ~Menomae no Mukou e~ 8,846
13 Kuwata Keisuke Honto wa Kowai Ai to Romance 6,909
14 V6 only dreaming / Catch 6,824
15 Kudo Mayu Tomorrow Song ~Ashita no Uta~ 6,362
16 Watarirouka Hashiritai Gyu 5,829
17 KARA Mister 5,595
18 Fukuyama Masaharu Hotaru / Shounen 5,543
19 Okuda Tamio Saikyou no Korekara 5,332
20 Aoi from Ayabie MI DA RA 4,831
21 Hannya, Fruit Punch Punch Shitatte Ii n da yo 4,036
22 Nagaho Yuki Tappizaki 3,655
23 miwa chAngE 3,386
24 Kuraki Mai SUMMER TIME GONE 3,342
25 Nakashima Mika Ichiban Kirei na Watashi wo 3,325
26 D=OUT Psychedelico∞Psychedelico 3,254
27 BIGBANG BEAUTIFUL HANGOVER 3,210
28 Perfume VOICE 2,838
29 Nishino Kana if 2,787
30 HO-KAGO TEA TIME NO, Thank You! 2,594
ORICON ALBUM SALES: TOP 30
# Artist Album Sales
1 JUNSU / JEJUNG / YUCHUN The... 139,708
2 Superfly Wildflower & Cover Songs: Complete Best 'TRACK 3' 63,828
3 Himuro Kyosuke "B"ORDERLESS 57,662
4 Quruli Kotoba ni Naranai, Egao wo Misetekure yo 33,962
5 Angela Aki LIFE 25,370
6 Tamura Yukari Citron no Ame 20,372
7 ARASHI Boku no Miteiru Fuukei 16,634
8 Kobukuro ALL COVERS BEST 14,081
9 clear Dearest 12,727
10 Ando Yuko JAPANESE POP 11,102
11 Tortoise Matsumoto Myway Highway 9,697
12 Domoto Koichi BPM 8,731
13 m-flo m-flo inside -WORKS BEST IV- 7,397
14 Underworld Barking 7,002
15 INFINITY 16 LOVE 6,188
16 Katy Perry Teenage Dream 6,030
17 WEAVER Shinsekai Souzouki.Zenpen 5,615
18 RIP SLYME GOOD TIMES 5,404
19 MAX BE MAX 5,222
20 faylan Polaris 5,157
21 Inaba Koshi Hadou 5,125
22 Charice Charice 4,938
23 Nishino Kana to LOVE 4,757
24 Oasis Time Flies… 1994–2009 4,621
25 BEGIN BEGIN no Shimauta Otomotakeo 3 4,308
26 The Mirraz TOP OF THE ****'N WORLD 4,169
27 TRICERATOPS WE ARE ONE 4,097
28 Various Artists You're Beautiful Original Soundtrack 3,960
29 Clémentine Animetine ~Bossa du Animé~ 3,925
30 knotlamp Dot of the Galaxy 3,784
Im feelin the song after listening to it 3 more times 
I was just watching that