There is, in my mind at least, some confusion between discoverability and promotion. That is, I want people to be able to find my podcast, which means I both need to promote it where the ears are and, if possible, make sure the ears can find it.
@jeremycherfas Yeah, I wish there were some happy medium between the feeling of shouting into the void and the feeling that, at any moment, a million screaming randos might show up on my doorstep. I think you are right that it the slow, hard work of building community with webring-like tools is probably the best approach.