Valve has revealed the top ten sellers on Steam for the week ahead of Black Friday's promotions.Call of Duty: Black Ops II leapt to first, as its launch in the middle of the week no doubt boosted the title after making an impact a week earlier with pre-orders.Assassinís Creed III canít be considered a slouch as a runner-up to the latest CoD blockbuster, while Hitman: Absolution finishes a respectable third right ahead of former champ Football Manager 2013.Indies Natural Selection 2 and Chivalry: Medieval Warfare continue to perform well beyond launch, finishing seventh and eighth respectively.Call of Duty: Black Ops IIAssassinís Creed IIIHitman: AbsolutionFootball Manager 2013Darksiders IIXCOM: Enemy UnknownNatural Selection 2Chivalry: Medieval WarfareBorderlands 2Counter-Strike: Global Offensive