One of the best things that the owners of stations running HD can do to 'sell' the product is to put compelling programming on the HD2s and 3s. For the most part, they don't do that at all. In most larger markets I've visited, there is perhaps 1 interesting format on an HD2. However, most seem to be either extensions of the parent station's format, a feed of a co-owned AM signal, or something of extremely limited interest. Oh yeah, or a format that was recently blown out on analog and is now running as a jukebox on the HD2 of its former home. Really uncomfortable in some cases to tune in. Such as in Chicago, where the former smooth jazz on WNUA 95.5 was relegated (without personalities) to HD2. The main channel is Spanish. So, whenever you turn on the radio, you initially get Spanish blaring at you until you can lock in the smooth jazz HD2. Awkward at best.
And tellingly, many of the smaller markets have the majority of their stations with HD signals only running an HD1. As I traveled across the "fly over" states (a term I dislike, by the way), I often found an HD2 only on the local public radio station. The others running in HD were only feeding an HD1. No subs.
In other words, aside from a few notable exceptions, there's very little worth listening to on HD radio. The allegedly improved sound on the HD1 versus analog isn't really worth the cost and trouble to get an HD system. And most of the subchannels are really not worth spending any time with. Even the best of them (usually musical formats missing elsewhere in the market) are basically jukeboxes without any jocks or local content.
So, the proponents of HD radio are not doing anything to further their cause aside from pounding away with ANNOYING ad campaigns that are only half a step above "cars for kids." Horrible marketing and implementation of the technology. Put a bunch of stations on the subs that people find interesting (and feel that they are "missing") and HD radios would sell a heck of a lot better. Then again, almost none of the HD subs are ever promoted so most people in a given market are blissfully unaware of what they are "missing" anyway.
The whole HD thing is a technology that's too late. Internet-based streams are where we're headed. Not HD radio (a misnomer if ever there was one).