We have an Emporium-like store which houses multiple brands and would like to know whether it would be possible to have separate Newsletter sign-ups for each brand on the site. So when customers sign-up to a specific brand newsletter they only receive newsletters from that specific brand and not from all brands.
You can add a tag to the customer base on the brand they signed up. Use the tag when sending newsletter (this depends if you are using apps to sent newsletter).
In you newsletter section, you will need to add an option on which brand the customer is signing up and place a tag on the customer. This will require custom edits and will need to hire a developer to do so