Substack publishers can now set up several subscriber group chats, called channels, inside one publication. Each one can be open to everyone or to paid subscribers only. The same release adds tagging and editing in chat, lists, freewalls, metered paywalls and scheduled emails to segments.
For a brand, the useful part is segmenting the conversation. People who pay for one topic can talk about that topic without the noise.
And the freewall collects an email before the full post. Substack says you can export both free and paid subscriber emails, so the list stays yours.