Sounds reasonable to me, pretty much everyone who bought an XB1 is going to get Halo

Nope wrong. Destiny made 325million on software fw and sold 4million. Halo made 400millionand the bundle must have done more than 200k and controllers around 100k so thats 105million. Now lets subtract that from 400million and thats 295million. Halo 5

Based on MS's PR. On the assumption that no other Halo game sold 4 million in its first week (which I don't think we know absolutely, but it seems to be a reasonable assumption based on the information we do have, no matter how accurate we think it is). MS would without doubt be highlighting that Hal 5 sold more units than any past Halo game. While it is very plausible to imagine MS not mentioning actual sell through if Halo 5 sold an average amount (i.e. about 3.5 million) for the Halo franchise, if Halo 5 actually sold the most of any Halo game there is simply no way MS would not mention such fantastic, amazing and completely unexpected news. It would literally be the biggest gaming highlight of the Xb one generation to date. You don't hide that sort of information behind total revenue, player hours and req acquisitions.

So, unless you think a 4-4.4 million opening week is average for Halo rather than a new series record, about as certain as it can possibly be that Halo 5 sold less than 4 million over its first 7 days. Do you think 4-4.4 million opening week is average for Halo? If so then sure you have a rationale for concluding that this could be the sales number for Halo 5.

There is one consideration of course. The difference between what VGC will publish as week 1 and what MS is announcing as week 1 is Sunday, and to a lesser extent Monday. Can Sunday and Monday cause Halo 5 sales which are probably somewhat behind the VGC week 1 of Halo 3 (the current VGC Halo week 1 record holder) to go over 4 million? That's a pretty interesting question. The thing is, if Sunday and Monday gets Halo 5 over 4 million, then it means Halo 5 VGC week 1 + 2 will most likely be above Halo 3's Week1+2. And that is very hard to believe.

Despite how much people like this game and want it to succeeed are we really going to stretch credulity to the point where Halo 5 has the best sell through of any Halo game? Bearing in mind that according to most non-VGC reports Halo 5 is the lowest or near lowest selling week 1 main Halo game in the UK, which is Halo's number 2 market.

4-4.4 million would be crazy good. About 3.5 million would still be a lot for it considering the x1's situation. 

Anything above 3 million will be a very good result, and with all manner of permutations that can be estimated from the MS PR a figure North of 3 million is within range.

What I wonder is what they actually mean by highest attach rate. This is the actual sentence in the PR "With the highest week one attach rate for a Microsoft first party title on Xbox One ". They don't say attach rate reltaive to console LTD. They may mean attach rate relative to console sales in the same period. Which lets say for argument's sake and for ease of calculation is 3 million games / 300K consoles meaning an attach rate of 10:1. That is one possible interpretation of the attach rate statement. And of course by that metric the Forza attach rate is pretty shitty at about 0.3:1 since it launched on the Xb one launch week.

So we don't even really know what MS means by attach rate. If they actually mean attach rate relative to console sales for the week what is the best so far? And does that give us a number that is within the realms of possibility?

Reading through it again I bet you that's exactely what they mean. During the Halo 5 launch week MS sold X copies of Halo 5 for every Xbox One they sold. That's how retailers meassure attachment rates, so I'd be surprised if that wasn't how MS was meassuring it.

Needless to say the PR surrounding the launch of Halo 5 has been confusing, and we won't really know much about how it did until NPD.

Halo underestimation? When will you people learn. It's halo.

It'll be front loaded with decent legs. 4 million including digital is very plausible.

Halo should have a big first week. What will be interesting however is to see if it'll be the lowest selling mainline Halo game.

I think it sold around 3.8m.
~350m= 5.2m Halo 3 for just software.
~400m has some subtractions from hardware and microtransactions.

A year ago Halo sold 60m. The franchise got 5bn with Halo 5. Without Halo 5 it is 4.6bn.
Using proportions we get 5bn x 60m / 4.6bn = 65m
That suggests 5m but it is obviously less due to Halo sales within a year and the PR suggesting it is both hardware and software this time.

So my rough guess is 3.8m-4m

Not sure what the history in terms of sales numbers for each game at launch have been, so can't speak for how likely four million sounds. I don't actually think that Halo 5 flopped, or did poorly, BUT I don't believe its unit sales (in terms of how many copies are now in the hands of customers) will have broken any records.

Their statement did come across with more than a little in the way of spin, but my theory on that wasn't that they were trying to hide bad sales, or even disappointing sales, but that they wanted to turn a 'Win' ('Halo 5 Sells Well Within Expected Numbers, Everyone Makes Bank, Investment More Than Repaid And Consoles Are Moved As A Result!') into a 'Big Win.' ('Biggest Halo Launch Ever!') The Win is nice, but largely expected from a series that sells like hotcakes on a regular basis, and likewise moves consoles; people would offer the usual congratulations, fans would celebrate, but it'd still be within expectations and word would likely fade pretty fast.

But the Big Win means that, even by the standards of the franchise itself, it is an exceptional success, topping even the nigh-legendary Halo 3. This unexpected runaway hit turns into mass headlines, fantastic PR, etc, etc, all that further boost the title's image as a desirable must-have, (along with the console it's featured on, of course.) 'The Most Successful Halo Game Ever' is quite a feather in the cap, after all, and a great way to kick off the holiday season. Heck, the statement itself called the game 'The anchor title in the greatest holiday games lineup in Xbox history.' What better anchor than the biggest Halo of them all?

Now, did it sell enough actual units of the game to top Halo 3, or others? No clue. Even if Microsoft didn't release specific numbers, though- fair enough, as there's precedent- I can't help but figure that if they KNEW they'd sold more units of Halo 5 at launch than any other Halo title, it would have been mentioned, even if without going into nitty gritty figures. I mean, they threw every OTHER positive statistic they could out there, including how they broke the record for people watching their launch broadcast, nobody thinks 'Oh, and more gamers chose Halo 5 than any other Halo game before' would have gotten in there too?

That they didn't say it suggests they were left with two options; either use unit sales and describe the game as the second or third-fastest selling (whatever it was) Halo title to date, a respectable but somewhat less spectacular title... oooor opt for the bigger 'Best Launch EVER!' title by just keeping the way you define it very... focused. =P