Microsoft's target for Halo 3 is a US$155 million opening day which would surpass even the opening box office record for a movie in the U.S. (Spider-Man 3 with US$151 million).  The previous entry in the Halo series opened at US$125 million so it will be interesting to see if they will be able to beat it so soundly.

What I'm really curious about is exactly how many copies are going to have to be sold to get US$155 million...  Any numbers would have to take into account the higher prices of the limited and legendary editions of the game.

http://www.gamesindustry.biz/content_page.php?aid=27639

Thats a big target maybe not imposible for Halo(i dont see why its a big deal and i have played 1 and 2).

well, thats roughtly 2.5m standard edition games, which if we believe the 4m retail preorders, then if microsoft ships all 4m, then it'll be no problem for day 1 sales.

don't know...Halo 2 could count on a much wider userbase at the time of its release

Have you tried online or co-op? I haven't got mine online yet, but playing the campaign through with a friend makes the game orders of magnitude more fun.

And i dont think every X360 owner is gonna buy Halo3.

 I have played on coop and it is good but it still isnt what all the Xboxfans say it is IMO.

It would need one day sales of somewhere in between 2-2.5 million. Since it has already surpassed 1 million preorders it would be interesting to find out the percentage of people who usually preorder a videogame versus opening day sales of the game.

At this point I imagine that Halo 3 will have somewhere in the realm of 1.5 Million Preorders, and then perhaps as high as 1.5 Million in Retail sales for a Total Box Office "Top" of around $186 Million in best case scenario (That is accounting for the Limited Editions too).

(GOING FROM NA NUMBERS ALONE)
There are roughly 6.6 Million 360's Sold in US. Gears of War had an opening day Attach rate of 1/6 (very good), Halo 3 ALREADY HAS and Attach rate of roughly 1/6 (One Million Preorders). Total 360's Sold in the US should be at least 7.2 Million when Halo 3 Launches. Halo 3 will have an even better attach rate.

My prediction is at least $158 Million.

Obviously... if they thought every 360 owner would buy it their goal would be more like $500+ million :-p

I don't know how these numbers work... if they count retail prices or what... So basically what I am saying is these numbers could be 10 folds off but just to show you how feasible this goal is.

They made approx 500k legendary editions. (correct me if im wrong here... i am pretty sure i read that, but can't find it to verify)
They already have 1 million pre-orders of the game. (http://kotaku.com/gaming/microsoft/halo-3-fastest-pre+order-ever-287713.php)

500k * 130 = $65 million
500k * 60 = $30 million

Ignoring collectors edition they already have $95 million, 7 weeks before the game is launched.

Again.... I could be wrong in 10 different ways... just saying these numbers are not insane.  All of that aside, im with you I don't see why Halo is so great.  But, I was playing PC shooters that were 10x better than console shooters for years before Halo 1 was ever released.  And, I will be buying halo3, purely so I can play with my friends!