Best-selling tactical shooter videogame

Best-selling tactical shooter videogame
Who
Valve Software
What
18,664,972 unit(s) sold
Where
United States (Seattle)
When
28 January 2016

According to Steam Spy, Counter-Strike: Global Offensive by itself had sold 18,664,972 units by 28 January 2016, over 7.5 million of which have played in a given fortnight.

According to VGChartz as of 21 March 2016, Battlefield 3 (EA, 2011) had global sales of 17.31 million.