Content delivery is not optimized for the technical stack used by an overwhelming majority of people. The technical stack of people who aren’t particularly tech-savvy, especially those who are old (over ~60 years), is often a messaging application like FB Messenger or WhatsApp. They currently do not have a way to ‘subscribe’ to Substack newsletters or podcasts or Youtube videos in the messaging application that they use (see below for an illustration of how this may look on the iPhone messaging app.) They miss content. And content producers have an audience hole.
A lot of the content is distributed only via email or distributed within a specific application. There are good strategic reasons for that—you get to monitor consumption, recommend accordingly, control monetization, etc. But the reason why platforms like Substack, which enable independent content producers, limit distribution to email is not as immediately clear. It is unlikely a deliberate decision. It is likely a decision based on a lack of infrastructure that connects publishing to various messaging platforms. The future of messaging platforms is Slack—a platform that integrates as many applications as possible. As Whatsapp rolls out its business API, there is a potential to build an integration that allows producers to deliver premium content, leverage other kinds of monetization, like ads, and even build a recommendation stack. Eventually, it would be great to build that kind of integration for each of the messaging platforms, including iMessage, FB Messenger, etc.
Let me end by noting that there is something special about WhatsApp. No one has replicated the mobile phone-based messaging platform. And the idea of enabling a larger stack based on phone numbers remains unplumbed. Duo and FaceTime are great examples but there is potential for so much more. For instance, a calendar app. that runs on the mobile phone ID architecture.