the reason odst is going to sell about 6m copies
odst didnt introduce any new competitve multiplayer(the main reason people buy halo)
its single player was only 4 hours long.
average graphics
so basically people bot odst for a 4 hour campain that was only average and a horde mode
the reason reach is going to sell more then 12 million copies(more then 3)
new competitive multiplayer(the main reason it will sell at least 10 million copies)
single player will probably be at least 8 hours
very good graphics
huge marketing campain.
the much more xbox users(there was about 18m users when 3 came out and there will be more then 40m when reach comes out)
Halo MCC will sell 5+ million copies(including digital)
halo 5 will sell 10 million copies(including digital)
x1 will pass ps4 in USA, and UK.
