I think an interesting feature that is not complex to implement (hopefully) is to allow the user to choose a segment of the members they want to send a newsletter to when publishing a new post.
The segmentation can be as simple as using the label data that we have of each members.
This can be the foundation that other features built on, such as:
+1
If by user you mean staff / author, this is possible - you can even configure the default tiers/labels:
I think he is referring to allowing the user to select a label that has been created by an admin user. That’s my understanding and that is what I would, for my use case, would like to see.
If we have several topics it would be great to be able to allow them to select what to subscribe to based on labels.
Yes the idea is to have an option on the new post page so we can choose which label (member segment) the newsletter will send to. On a post by post level not as global newsletter settings.
The screenshot I shared is for the default, you can choose the same member labels on a post-by-post basis 
I took the custom approach to allow users to select interests on signup which are labels created within Ghost. Hopefully, the Ghost team implement ca something like this on the portal signup process.
