"Counter-strike" is pretty much the father of the modern first-person shooter, providing inspiration for an entire generation of PC shooters to follow. The game started as a modification of Valve's "Half-Life," but has since spawned a legendary competitive community.
The latest game in the series, "Counter-strike: Global Offensive," has seen a number of major changes to make the game more sustainable and provide new incentives for the dedicated player base. Valve began introducing cosmetic weapons and other rewards to the game, and players created their own economy by selling and trading rare items for real-life cash.
The game's popularity as a competitive esport and the odd economy surrounding the game have helped "Counter-strike" continue increasing its playerbase years after its initial release. Currently, more than 300,000 people play it on a daily basis.
In December, Valve took a major step by making the game fully free-to-play.