Every day Spotify adds enough tracks to fill a medium-sized record collection (about 10000), as they sign deals with new labels and new deals with old labels. The reason Pink Floyd might be added is that EMI owns their music, and they have already signed a deal with Spotify.
EDIT: The song reached 350K streams yesterday, and the tweet from 14th of July said 100K streams. That's rocket speed, man!
@Spotify
#floydcountdown