Bungie has revealed that one billion matchmaking games of Halo 3 have been played since its release. That's insane. To put that into perspective, Halo 2 is currently sitting at 798 million games played and has been out for much longer. Although to be fair, people are probably done playing Halo 2 for the most part.
Using its crazy database skills, Bungie has determined the exact amount of time spent in matchmaking, which does not include singleplayer, offline play, or custom games:
Total Matchmaking Playtime: 2,023,153,340,764 seconds or 64,109 years.
I'd be really interested in seeing where Call of Duty 4 is with its PC, PS3, and Xbox 360 data, but this is really a great accomplishment for Bungie.
By the way, I've contributed 991 games to that total! What about you?