If you are a TechNet or MSDN subscriber, you’ll notice that you are only alloted 2 keys maximum (or 5, depending on the level of subscription) for most products, instead of the original 10. Not so bad, but even Microsoft’s own employees thought it was a system bug, rather than intentional.
However, MS made the switcheroo without first informing its subscribers of the tweak to its TechNet small print. Product keys are used by Microsoft and other software vendors to certify that a user’s copy of a particular program is genuine, and they typically require online activation.