maybe they were too dumb? their expensive kindle readers (not fire) can subscribe/unsubscribe to those special offers anytime. just sign in to their amazon account and tick on subscribe to special offers.
They added that later on from what I can remember.
I just purchased a Kindle Keyboard 3g with Special Offers last week but I don't see any ads at all. When I go to the menu button in home I don't see a Special Offers link their either. smh