"Ted Koppel" wrote in message
...
A question about Satellite radio (XM in particular)

Obviously they have some way to know that they are broadcasting to an
individual receiver, else (a) they couldn't sell and send signal to
specific devices who pay and not to others and (b) they can deliver
specific programming (Playboy channel, Opie and Anthony) to specifc
receivers.

I don't see how XM can know what channel you are listening to, unless you
tell them. Receivers do not transmit data anywhere, and they are not
connected to a phone line.

XM would know if you are interested in a premium channel because you are
subscribed to it.