In the music industry 1,500 steams equates to one sale. Most streams come from subscritptions services like Spotify, Apple music, Tidal, pandora etc. This was put in place because streaming sales started to become more relavant while physical sales became irrelavt.
Something similar is beginning to happen to the gaming industry because were seeing more subscription services and these services are gaining million of active subscribers. the 1500 to one ratio in music probably wouldn't work for gaming since gaming is more niche in comparison to the music industry.