With 65 Million Steam accounts, it can be said that approximately 0.9% of Earth's 7.121 billion total population uses Steam, Valve Software's Digital Distribution system, and rising with a 30% growth in active accounts over the course of last year.  This of course does not take factor in things such as idle accounts (I myself once witnessed a Steam Group of hundreds of different accounts owned by the same person for the purpose of collecting data of Team Fortress 2 item drops.) as well as accounts owned by who no longer use steam for one reason or another.

This massive population of Steaminites is unsurprising due to the rising popularity of PC gaming combined with new and creative features consistently being added to the service such as Trading Cards, Family Sharing, Early Access games, and Steam workshop. On top of this, the release of Valve's new living room-focused hardware, Steam Machines, the number of Steam users may increase exponentially. Who knows what the future holds for Steam and its users? Only time will tell.