In one of the more interesting promotional efforts we've seen come from Spotify, the company is promising to unlock Pink Floyd's entire album catalog once fans stream the band's iconic song "Wish You Were Here" 1 million times. The track — and presumably the discography that will follow once the milestone is reached — is pulled from the remastered Pink Floyd albums released in 2011. There's no counter visible, so it's difficult to assess the progress being made so far, but Spotify is telling listeners to keep watching its Twitter feed for the latest. It's also taken to Instagram to get the word out.

Pink Floyd's albums are available from iTunes and Amazon MP3 as paid downloads, but availability among subscription services is a bit more limited. Until now classic albums like Dark Side of The Moon and The Wall have been absent from Spotify and competitor Rdio, though the band's music can be found on Pandora (and presumably will stream on iTunes Radio in the fall). The deal between Pink Floyd and Spotify is likely already finalized, but the million-stream target is a clever way to build up hype around a major artist addition.

Update: Notably, Pink Floyd is available for streaming from Google Music. Thanks, sideshowscott!