Your post makes no sense. This site has the first week sales at 3.84 million. Last time I checked 3.84 million is more than 1.36 million for the second week which would add up to 5.2 million. So unless my math is wrong 3.84>1.36.  Also that would be a 65% drop in second week worldwide sales.

it was 3.8 at the end of of 29, if it sold 1.2 in a week or so, then yes its about 5 mil

i think its around 4.5-5 mil

yea where are you guys getting such low numbers, this site itself says it sold 3.84 million units already

5.2 million is very unlikely. Thats about 1/2 of the user base and if the RRoD thing was true that it was at a 33% failure rate then its not happening. Who knows they could be off with the ring of Death.

Gears sold 4.81 and still sells 15-20k each week so 5.2 is not beyond insane.

If those numbers are true, I'm rather curious as to how the Mario and Brawl titles do.

I found a flaw in the logic. Halo is not a console only brand. The first two games are available on the PC. Which could easily account for a million sales combined at this point easily. The original Halo sells for twenty dollars on average on the PC. The writer is taking certain liberties with the numbers by doing the math themselves.

While the number is possible most would argue it is not plausible. That said there is a strange psychology at work in hype. I refer to it as the pack mentality, or the me too mindset. Which will spur on sales of items even though the buyer might not have a real appreciation of them. I have seen it too many times with too many different things to discount it. Remember all those people that bought the death of Superman comic, or the people that bought a first edition Harry Potter book. How about all those people that had to have a beanie baby even though they had no real interest other then saying they had one.

i think first week might be a bit under tracked in USA it did at least 2.1m ($80 av) and up to 2.4m ($70 av) im sure it did more than 200k in 4 more days, possibly 2.8 - 3m first week

5.2m is very possible it will have majour drop ofss until thanksgiving, i think it will pass 10m WW easily in its lifetime just because sales are so good on 360

 Just for the record,that's not a flaw in logic.  This is what this site has for Halo 1 and 2 only on Xbox.  Halo = 6.43 million Halo 2 = 8.29.  If you add those together you get 14.72 million.  That is EXACTLY what microsoft themselves said both games have sold and is what the article uses.  Let's say Halo 3 is "only" at 4.5 million worldwide when this weeks numbers are out.  Are you trying to say Halo 1 and 2 only sold 700k units combined on PC?  I would almost guarantee they aren't adding in PC sales in it.  

I would not be surprised if this is true.