Comment Starsiege: Tribes took quite a hit from piracy (Score 4, Informative) 1115
No two ways about it, the game sold poorly, but was quite successful with players. I certainly don't mean to imply be any stretch that every player represented a lost sale, but I definitely believe that the complete ease with which the game could be copied (ie, right click on the install folder, and select "ICQ this to my buddy") led to very disappointing sales.
Most games that sell poorly are poorly made games: the market is the final judge of quality. However, I also firmly believe that had Tribes had some basic form of copy protection, the sales would have been much much stronger. I hate that I am now sounding like I advocate loads of DRM, but Tribes represented an almost pathological case with its utter lack of any protection, and I think this wound up hurting sales very markedly.