This is actually an old article, almost 2 years ago. If I remember correctly, XM has since changed its definition of a subscriber to include cars sitting on dealers' lots, too.
It's really not all that uncommon. I seem to remember hearing Mattel counts toys as sold as soon as they're off the loading dock and on the truck. The process will balance itself out because, if too many toys are shipped and sent back, they'll have to count them as returned merchandise. With satellite radio, the process should balance itself out as well. If someone buys a car and doesn't activate the service, they should count that as a cancellation. If a car was totalled due to being waterlogged from Hurricane Katrina, that should be a cancellation as well.
