Bungie has released some official stats regarding Halo:Reach:
From September 14 to December 10, Halo: Reach players logged a collective 24 thousand years of battle. Those long, caffeine drenched hours in the online trenches resulted in 33 billion kills, 24 billion of which were covenant. There were 2.7 billion headshots, 210 million grenade sticks, and only 87 million Killed From the Grave achievements. The Unf-believable rank (40 kills without dying) was only reached 320,000 times, impressive when compared with the Killing Spree rank (5 kills without dying) that was reached 255 million times.
When grouped together, it’s truly amazing how much we can achieve, when we are motivated by addictive multi-player competition and trying not to get teabagged by our friends.
[Source]
