Halo3 sold to retail between 8-9mil games last year. So 13mil is possible on two systems, on a franchise that is alot bigger then Halo, plus GTA has about 5more months on the market then what Halo had.

But see, that's exactly my point, shams. Guitar Hero 3 has sold 11m copies - by virtue of being on ALL platforms. Grand Theft Auto 4 is NOT going to be on two of the highest-selling platforms, Wii and PS2. To look more closely at those Guitar Hero 3 sales:

PS2: 3.68m
360: 2.63m
Wii: 2.18m
PS3: 1.07m
"HD console" total: 3.70m

That's... not even remotely close to 10m.

Your Brawl example is similarly suspect reasoning (and I'm usually a huge fan of your posts, so please don't take any offense). While saying it sold 4m in two months is true, it's also rather disingenous, since Brawl is a front-loaded title like so many others. The opening week in America was 1.5m copies, and the first week in Japan sold 800k. We'll probably see another 2m units sold in those two territories by the end of the year, plus whatever Europe manages to contribute (another 2-3m?) That leaves us somewhere in the range of 8m units, which again is a great total - but not even remotely close to 13m.

The biggest logical flaw is this statement: "Pretend the platform is doubled, and add Europe - and its an easy sell of 10m in just 2 months." Doubling the size of the install base doesn't add up to doubled sales, because as install bases grow they also become more diversified. If this were not the case, we should have expected to see the biggest PS2 games sell 5x the top games on the Gamecube and XBox, which clearly didn't happen. (Instead, they sold about 2x more, 15m compared to 7m). It's impossible to figure out the exact relationship between growing install base and growing sales, but it's certainly not a 1:1 ratio.

I've yet to see anyone respond to my point that combining the top-selling lifetime 360 game plus the top-selling lifetime PS3 game still leaves you a good 2.5m copies short of 13m.

for one system no, combined yes

I don't think 13 million in 2008 will happen either.

I'm guessing around 18 million.

Flop on GTA4?...  I don't know about you, but I was here in 1997 when the first GTA came out, and the 2nd then London... and was there when it moved to 3D with GTA3, then VC, SA...played every one 100%... Not a single sequel has disapointed me in any way... I think most people would agree GTA isn't, and wont ever be a flop. Sales numbers can back that claim up. Keyword most people:)

nooooooooooooooooooooooooooooooooooooooooooooooooooooooooo

more like 15 mil.

6 mill on launch day?.!

Didn't San Andreas sell 12 million in its first 4 months?

Even if it's shipped numbers that's still mighty impressive for one platform alone. 

GTA has been known to sell several million copies

I don't know if its possible, maybe 3 million on each console which adds to 6 million total sold in 2008

One of two possibilities here

1. Game actually isn't that good compared to hype (see halo3) and will have huge launch and dwindle off fairly quickly. Resulting in sub-GTA:SA levels.

2. Game is really good and has huge launch and very good legs on both platforms. Thus greatly exceeding GTA:SA sales.

Either way, 10-15m by end of year should be easy.

anyone who thinks it cant make 10 million is crazy

13 million is optimistic, but in no way impossible especially if the install base can hit 45 million between the 2 consoles by the end of this year