Its pretty rare for sequels to outsell the games that came before it. Most sequels sell roughly the same amount, or slightly less (for example: MGS3 sold less than MGS2 despite being a better game)

I know COD WAW and COD MW sold much better than the previous COD games.

Fallout3 sold better than the previous Fallout games.

Halo 3 sold a few million more than the first 2 Halo games.

What other sequels have increased in sales over their predeccsors, and by how much?

Too lazy to look up the exact numbers, but:

Call of Duty 3 (360): 2 million

Call of Duty 4 (360): 7 milion

GT II to GTA III

many Wii sequels have sold more then their previous iterations on the gamecube

Yeah, GTA went from 3.5m to 12m

Actually, I think the reward might go to Mario Kart Wii

Mario Kart Double Dash: 6.96 million sales

Mario Kart Wii: 16.32 million sales

Difference of 9.36 million sales.

Thats because of the HUGE increase in user base.

But how many Wii sequels have outsold their Wii originals? I doubt Mario Galaxy 2 will out sell Mario Galaxy 1.

also...GTA 3 outsold 2... but it's quite obvious why. It's a completely different type of game.

Can anyone explain the huge jump in COD sales?

Read the post I just made.

Please do not include Ps1 to Ps2 sales jumps, or GC to Wii sales jumps.

The larger sales are due to user base.

I shouldve specified...I meant sequels to games that are already on the same platform.... so a Wii sequel to a Wii game... or a Ps2 sequel to a Ps2 game...or a 360 sequel to a 360 game....etc

Right...so let me get this straight?

Call of Duty World at War and Modern Warfare were on the same platforms as all the previous Call of Duties?

Fallout 3 was on the same platforms as the prevous Fallouts? All 3 were on PC, but we don't have sales data for those.

The first two Halo games were on the Xbox, Halo 3 is 360 exclusive.

So if you don't like me using GC to Wii transitions, don't do them yourself. You can't just change your qualifications in the middle of a thread. I was going off of your original post.

COD WAW and COD MW can be compared to COD3...all are on 360.

Fallout3 and the other Fallouts are on PC...

I compared the Halo games  with Halo3 because the user base for 360 and the original Xbox are close enough.

I just didnt want ppl comparing sales for FF1 to FF7 and stuff like that. Also comparing any GC game to the Wii sequel in sales is silly due to the huge difference in user base.