1. Adele - 30.5 million copies (2 albums)
2. Norah Jones - 27 million copies (3 albums)
3. Rihanna - 23.3 million copies (6 albums / most released)
4. Lady Gaga - 20 million copies (3/4 albums)
5. Taylor Swift - 19.9 million copies (4 albums)
6. Avril Lavigne - 18.8 million copies (4 albums)
7. Beyoncé - 18.7 million copies (5 albums)
8. Pink - 18.5 million copies (4 albums)
9. Madonna - 16.3 million copies (5 albums)
10. Alicia Keys - 15 million copies (4 albums)

11. Amy Winehouse - 14.6 million copies (2 albums)
12. Britney Spears - 13.2 million copies (4 albums)
13. Miley Cyrus - 12.4 million copies (6 albums / most released)
14. Susan Boyle - 12.2 million copies (3 albums)
15. Katy Perry - 10.3 million copies (3 albums)
16. Kelly Clarkson - 10.1 million copies (2 albums)
17. Mariah Carey - 8.9 million copies (2 albums)
18. Dido - 8.6 million copies (1 album)
19. Shania Twain - 8.3 million copies (2 albums)
20. Nelly Furtado - 7.4 million copies (1 album)

21. Gwen Stefani - 6.7 million copies (2 albums)
22. Carrie Underwood - 6.6 million copies (3 albums)
23. Christina Aguilera - 6.4 million copies (2 albums)
24. Celine Dion - 6.2 million copies (3 albums)
25. Leona Lewis - 5.7 million copies (1 album)
26. Shakira - 5.6 million copies (2 albums)
27. Pussycat Dolls - 5.2 million copies (1 album)
28. Dixie Chicks - 5.0 million copies (2 albums)
29. Fergie - 5.0 million copies (1 album)
30. Destiny's Child - 5.0 million copies (2 albums)

31. Duffy - 4.5 million copies (1 album)
32. Lana Del Rey - 4.3 million copies (1 album)
33. Jennifer Lopez - 4.1 million copies (2 albums)
34. Florence + The Machine - 4.0 million copies (2 albums)
35. Enya - 4.0 million copies (2 albums)
36. Emeli Sande - 3.4 million copies (1 album)
37. T.A.T.U - 3.0 million copies (1 album)
38. Whitney Houston - 2.9 million copies (2 albums)
39. Hilary Duff - 2.7 million copies (1 album)
40. Nicki Minaj - 2.7 million copies (2 albums)

41. Mary J. Blige - 2.4 million copies (1 album)
42. Hikaru Utada - 2.3 million copies (1 album)
43. Sade - 2.3 million copies (1 album)
44. Ashlee Simpson - 2.3 million copies (1 album)
45. Kesha - 2.1 million copies (1 album)
46. Sheryl Crow - 1.9 million copies (1 album)
47. Lily Allen - 1.7 million copies (1 album)
48. Corinne Bailey Rae - 1.7 million copies (1 album)
49. Jessie J - 1.3 million copies (1 album)
50. Lorde - 1.1 million copies (1 album)

8. P!nk - 18.5 million copies (4 albums)

I thought she sold more.

16. Kelly Clarkson - 10.1 million copies (2 albums)

She released seven albums since 2003 and only 2 made year-end charts?

How are Demi & Selena not on this list? They've sold a lot more than #50

alot of these numbers seem off

Adele, Leona, and Beyonce. All in the top 25.

And yes at them saying Leona only has 1 album. They better recognize that Echo and Glassheart were mixtapes.

edit: Though Spirit is close to 8 million now (and Echo still sold 2 million WW) and Adele is at 35 million albums sold. So this is off.

at Katy.

7. Beyoncé - 18.7 million copies (5 albums)
40. Nicki Minaj - 2.7 million copies (2 albums).

Gwen I thought L.A.M.B. had higher numbers but whatever, I'll take it

These seem...off to me.

Duffy released two albums and Christina, three.

Is this US only?

DIL + B'Day + IASF + 4 > 18.7

I've never heard of Norah Jones.