a few of my buddies pirate games sometimes. but they usually end up buying the games because very often it is either very hard or impossible for them to get it to work online, which is where they play most of the time. so, basically, they pirate the game to see if they like it, and how well it works on there system, than, if it works well, and they like it (which is usually the case) they buy the game. so basically, it seems that if game companies made a demo (and a usuable demo, that was basically the full game with restrictions of some kind), they could cut down on some of the piracy.
Like, Planetside, they had the entire game free for a while, but u could only level up to a certain point (level 6 if i remember, which isnt much, but it worked). and my friends and i played it for a while, and loved it, so we decided to pay for it so we could do more in the game, it just seems like a much smarter idea.