Mac users interested in Spotifree 10.5.8 generally download:
Spotifree is an OS X app that automatically mutes ads on Spotify. The app is polling Spotify every 3 seconds to see if current track has a track number of 0 (as all ads do). If it is, Spotify is muted for a duration of an ad. When an ad is over, the volume is set to the way it was before.
