The figures from the first half of this year show that CD sales, not surprisingly, are falling. Compared to the first half of last year, they are down by more than 4 percent. More than making up for that decrease is the tremendous growth in digital downloads. Downloads of complete albums soared by 126 percent, while downloads of individual tracks grew by a mere 77 percent. As you might imagine, individual track downloads still dwarf those of complete albums, lending credence to the theory that the album as an art form is dying.
Read this article from Ars Technica