If they pirate your game and play it AND if they wouldn't have bought it anyway, you should be happy because they're not giving money to your competitors: they don't have the time for it because they're playing your game. It didn't cost you anything but you're gaining something. Obviously people plays several games at the same time, still this reasoning works and in many markets. If they are happy enough with your pirated games, music, videos, clothes, bags they won't buy your competitors products. If your sales are higher than theirs, pirates are helping you to starve your competitors.