It's worth pointing out that it's an Alexa 300k site already (prior to this HN post's effect), which is some objective evidence that author is skilled at building a site and/or community.
I brought up your Twitter followers because it seemed relevant to your accomplishments in this post, given that they were directly responsible for ~1/4 of your email list and likely indirectly responsible for many more subscribers (Signal boosting your PH launch, for example).
Having an audience seems to be the most important thing for a lot of product launches, so I'm always curious about how people built their audience.