Gears of War:
Week 1 - 910k
Lifetime sales - ~6 Million
Time taken to hit 4 Million - 28/35 Weeks
Gears of War 2:
Week 1 - 1.9 Million
Lifetime sales - ~6 Million
Time taken to hit 4 Million - 8 Weeks (With a November launch)
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Right. Now I've got that out of the way... I have to wonder if people seriously think a Gears of War game can open up to 4 Million in a single Week and beat Halo. Seriously. Halo Reach sold more in its first 10 Weeks than either Gears or Gears 2 did in Years on the market.
I say 2.5 Million max Week 1.