With Galactic Civilizations II, we put no copy protection on the CD. But to get updates, users had to use their unique serial # in the box. That’s because our system is backed by TotalGaming.net’s unique SSD service (secure software delivery) which forgoes DRM and copy protection as we know it to take a more common sense (I think so anyway as a gamer) approach of just making sure you are delivering your game to the actual customer.Link, Link to buy Galactic Civilizations II
Any system out there will get cracked and distributed. But if you provide reasonable after-release support in the form of free updates that add new content and features that are painless for customers to get, you create a real incentive to be a customer.