I bet on some level they know and don't care. If you're buying a cheapo key off of ebay then chances are you were never going to pay the full price. Meanwhile

I bet on some level they know and don't care. If you're buying a cheapo key off of ebay then chances are you were never going to pay the full price. Meanwhile they're still using the software, learning how it works, and growing the Windows ecosystem further. Vaguely like a loss-leader that gets people in the door.