"The single biggest piece of advice I have for you: if you have someone's email address (+ permission) you have an earned relationship. If you have to beg a platform to contact them, the platform owns the relationship."
But it is this one that really nails it for me:
"Youtube subscribers, Twitter followers, Facebook fans, and all analogous relationships are not defensible assets in the way that someone expecting mail from you is. "
This is why I ask people to get on my mailing list. I email rarely, if it isn't about music or a live gig, I don't. I email personally; have conversations with my listeners; meet in real life. I might be hopelessly late to this party, but it's great to be able to sit down and find something about another person in a 1:1 conversation, name, face, and everything, and not by checking out their online profile.
That said, if you read the linked thread, this site is not a platform, and I'm not after "enticing some portion of the audience to join me on my platform". As a location point, a site, in a world of noise, it's the only beacon to accurately fix my position, without an algorithmic middleman jamming the signal.