It was like they let an engineer come up with that tagline. It's literally accurate but didn't clearly describe the advantages an HD radio tuner might have brought a consumer. It probably have been better to advertise specific programming. Here's a couple of ad scripts to illustrate what I mean:
"Smooth Jazz: free on your radio with an HD Radio receiver. Tune to 101.3 channel 2. Available at Best Buy, Ward's, Radio Shack and other electronics retailers. Look for the HD Radio logo."
"ESPN Radio around the clock. Your favorite ESPN personalities discuss the NBA playoffs all week. Listen to 93.1 subchannel 3, on an HD Radio tuner. Available in all Pioneer receivers, now on sale at K-Mart"
Another thing I never saw: external advertising. An ad in print or outdoor media might have captured certain consumers who were put off by a format change. Keep in mind that HD radio came about in the era when Smooth Jazz and Oldies were dying, so there were some displaced customers.
The problem today isn't the age of the audience, but the lack of audience size. According to Nielsen, all HD subchannels combined earned a 0.1 share and 24,000 cume in the latest Phoenix book.