@SlipperyMooseCakes
Not all games have demos, and more to the point not all game development cycles allow for the making of a demos. It is really dependent on how the studio develops games. In the case of Halo 3 it would have actually been a atypical demo in that it would have to have been developed post release. After the time in which a demo can actually generate the vast majority of sales that a demo will generate.
You have to remember Bungie opted for a public beta with a short time frame prior to release. This meant they had a short time to rectify balance issues. So there probably were no assets to dedicate to developing a demo. They were probably working on code up until launch day, and actually had to continue work after launch to ensure stability, and that there were no game breaking cheats that were going to be exploited.
Then they had to get right to work on new projects, and the remaining team had to get to work on content expansions. In the end they probably didn't have the time to dedicate to something that was hardly essential. I ask you which is more important making a demo after the game has gone out, or developing content. For most owners this is an easy answer.
Then there is the danger of a demo depriving the game of sales, but not necessarily in the way you are thinking. For a representative demo you would have to include the online. Which is what most players are actually interested in. So then you have gold issues, and the real possibility that players will simply opt to use the demo rather then buying the game. Lets be real here a little bit of Halo goes a long way. Not to mention how a limited demo would fuck up the servers since those playing the demo may only get to play in a couple maps.
In the end there just isn't much of a need to make a demo, and in the end it would probably be more of a pain in the ass. That only drains money from everyone involved. The beta worked in truth, because it was limited. No need to overhaul systems to accommodate a demo, or any real need to develop one. The beta gave players the answer they wanted most of all.







