A Discourse instance (like this one) could serve as a substitute for a newsletter. You could (assuming the moderators allowed it) just start posting topics here under some common tag (your “Brand”) and start encouraging people to follow that tag.
If your musings became widely followed, you might gain moderator privileges. Then you would be able to do things like create a Group that people can join via email. It would act just like a newsletter in most respects at that point.
