Not to belabor an issue that's already been well discuss (as I came into the thread late also) but my final conclusion about CD antipiracy codes is this; while it may stop initial attempts at piracy, the pirates will ALWAYS find a way around it, such that the scheme becomes moot to them; while some portion of regular customers who pays for such discs will ALWAYS have problems and returns the discs, ultimately hurting sales. So in the end, the pirates crack the scheme while the publishers' themselves have hurt sales. So who really wins?
Take a hint from the 800 pound gorilla in software protection schemes (M$). Despite the many phone home registration things that Gates puts into his programs, pirates have always found ways around it, but the bulk of customers do pay for it. If you make it so troublesome for them even after they pay for it, they may look to the dark side just to get the thing to work.
The aspect of "proper care of discs" is also moot. The hardier a technology, the longer lasting. If something is built as a house of cards that can easily collapse, then product longevity is usually adversely affected. It's more about human nature, buying patterns, and the subjective sense of product value rather than coding.
