Console market is massive when compared to PC Games.
I'm sure Agent will agree (fellow GAME employee ) that console software outsells PC software on a scale of 5-1 or more at least. The exception being PC budget maybe but thats just because GAME does a lot of 3 for £10 and 3 for £20 titles. Sims is also a rare case, damn EA...
An issue I was thinking about for a while is coming to fruition at this moment I think...
The PC market boom happened a few years ago. Everyone was buying PCs as you just simply HAD to have a computer because then you weren't on the net, you were doing your kids an injustice in regards to their education and you weren't with the times. It was almost socially unacceptable not to have a computer!
A few Christmas's ago the PC was probably at it's highest point on people's wish lists for whatever reason and so they were bought. That was then...
Times have moved on and so has technology. Ok so we as members of the Hexus forums are probably pretty clued up on our hardware and most of us have niinja systems O/C'd to the max. What about the general public? They still have the systems they bought back in the day when it was the "in" thing to buy a PC. They don't have the desire to spend another grand or so with Dell or Tiny to get another PC a few years down the line. Games are moving on and their systems are incapable of running them.
This hurts sales for the PC market. Xbox, PS2 and Gamecube owners have a rock solid guarantee that their systems will run every game they buy at an acceptable frame rate with acceptable graphics. Even the most expensive PC system has a possibility that a game won't run on it be it with a driver problem or some other form of incompatibilty. (Granted these problems are fixed in a matter of days but it can happen)
Example in case - The Sims 2. The original game didn't put a great strain on the system and it could be run on most PCs, part of the reason for it's success. I can just sense the amount of people that will want the Sims 2 and simply won't have a system capable of running it. All the little girls who play nothing but the Sims won't be able to use Daddy's office PC with Office and a few MP3s for the Sims 2 because it won't be up to the job.
Game just changed it's returns policy. Currently you can return ANY console title within 10 Days to refund it or change if you simply don't like, have finished it or just want something else - no questions asked. Granted it must be in pretty mint condition but its a nice option. PC Games are excluded from this - it used to be that they weren't. Reasons for the change are pretty obvious, people just bought the games, copied them and brought them back.
What happens when the Sims 2 comes out? People will either not buy the game because they realise it won't run on their system or buy and discover it doesn't work demanding a refund. I predict The Sims 2 will not sell anywhere near as well as the original Sims has because of this.
Farcry suffered quite a bit from this. Probably the first real next gen shooter and an amazing game - but how many people can run it?
Parallels can be drawn with HL2 and Halo 2 here. I would venture to suggest that the majority of people who have Half Life won't have a system capable of running Half Life 2 to a decent standard. On the other hand everyone who has Halo can run Halo 2 without a single problem (Unless Bungie produce the cockup of the century ).
On the Technology front I would say Half Life 2 will be the bigger hit but relatively Halo 2 will probably be a major technological achievement in the field of console gaming.
On the sales front...
... there's no competition.