A demo is a form of marketing and advertising. It's no different than putting out Mountain Dew flavors, TV spots, websites and viral marketing. Like others have said, some games benefit from utilizing the demo approach and some games benefit from getting splattered with huge commercials on Spike TV. Considering that a wealth of advertising and good word of mouth turned both Halo and Gears of War into marquee franchises shows that Microsoft knows more about whether the two need a demo more than any of us do.
Do note, that Sony provides a lot of it's first party titles with demos, but in the case of it's own behemoth, Gran Turismo, my American ass can't find a demo in the PSN store to save my life. Bottom line, it doesn't need one.
Tag: Became a freaking mod and a complete douche, coincidentally, at the same time.
