Some of the responses here explain why the PC games market is in decline.
That is, some people will be unsatisfied no matter what policy is created.
Galactic Civilizations II is a PC game that has no CD copy protection whatsoever.
We release free updates that I have a great deal of new content and new features.
But we have to have some way to know that the person downloading the update has the actual game. I don't see any other way around that. If we don't require the original physical CD in the drive, then there's no real verification that the person using updates even has the game.
So the policy is that a user types in a serial # and an email address. In exchange, users can then download the entire latest/greatest version forever afterwards even if they lose their serial #.
Now, if someone returns the game to the store after having created such an account, that serial # is tied to the email address. A person who buys the used game still can play the game. The physical good they purchase works out of the box. We are not required to provide any updates to the game, the game out of the box works fine. The extra updates are essentially a free service we provide to reward customer for supporting us.
Those users who purchased a used game (typically off of eBay or whereever) got it at a much reduced rate, which is fine. But if their account is tied up, then they just need to contact us and we'll provide them with a new serial # for a much reduced cost.
When someone buys Galactic Civilizations II they're really getting two things: (1) The game itself and (2) Lifetime access to Stardock.net which allows them to get new updates and full-redownloads of it. Item #2 involves having a serial # tied to an individual account.
Will such a system satisfy 100% of people? No. But given the alternatives (either CD copy protection or no free updates), I think this is by far the best option for the customer. As a gamer, I don't want to mess with CDs being in the drive and I want my games to keep getting updates after release. I also understand that if I don't have to keep a CD in the drive that there has to be some system in place to assure that I'm actually a customer before I download megabytes of free, non-required updates to the game.