I see problems in the future for XM Radio and Sirius. Terrestrial digital broadcast radio is rapidly expanding and soon will be available everywhere (in the USA), just like terrestrial digital broadcast TV is now. (Analog NTSC broadcasts END February 2009!)
Why should this be a problem? Satellite radio costs money for content. Terrestrial digital radio, like TV, is FREE- other than the cost for a digital radio to recieve it.
Once free digital broadcast radio is available nationwide, the one and only benefit fee-based satellite radio will have is you can listen to the same channel, playing the same stuff, nationwide. Great- if you're a long haul truck driver who is picky about music, but for those who never stray out of range of their favorite station, why bother with radio you have to pay to listen to?
According to the specs, Digital FM is CD quality while Digital AM is as good or better than Analog FM. Even better, radio stations don't have to expand their radio spectrum bandwidth to add digital. Radio channels were originally made as "wide" as they are because in the early days, analog broadcasting equipment was quite noisy and the channels had to be wide to avoid crosstalk between stations broadcasting on adjacent frequencies.
Modern analog radio equipment is very "tight", which leaves plenty of room in a channel for sending out a digital signal. For a station to upgrade to digital is relatively inexpensive, a single piece of equipment that costs around $25,000 and jacks directly into their existing system.
They can't encrypt the digital signal and charge for it because they're using their existing bandwidth that under the FCC licensing they have to provide programming at no charge, supporting the expense with commercials. (Or your tax money for "public" broadcasting and school stations.)
