Halo 2 sold 2.4 million copies the first 24 hours. And it sold around 4 million copies the other 2-3 months after launch.
Now, there are how many xbox 360 consoles sold? 11,5 million? Thats around the half of xbox 1 consoles sold when halo 2 launched.... and i think on 25th september, there will be more than 2.4 million copies of halo 3 sold (first 24h).
I think halo 3 will stay very long in the charts, same as halo 2 even now does
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