If people like your demo enough to play it for 12 hours, doesn't that make them more likely to buy the full game..?
Not necessarily. I personally love a good full-featured demo, but as a business matter it can have a real averse effect on sales especially initial sales. For example the UT2004 demo had such a great selection of maps (Facing Worlds, Torlan, Rankin, etc.) and gameplay modes that a lot of people didn't bother buying the full game (at least until months or years later when it had dropped substantially in price) because the demo gave them all they were really looking for. The Halo PC demo is another one which is still quite popular online almost five years after the full game's release.
As for Far Cry 2's lack of a demo, there will be a trial version of the game after it ships. It will just be an unauthorized one and found on the network of Bittorrent sites.This comment was edited on Jul 12, 23:48.