I've seen this question asked before, but with varying perspectives so thought I would throw this out again.
We have multiple workspaces with each workspace essentially defined as a product. If possible we would like to find a way to have each workspace have it's own unsubscribe token or link. From what I've read it doesn't look like there's many options for this type of implementation.
We do know of the option to have a field specific to each workspace that could act as an opt-in field, but due to specific circumstances, this would be difficult to implement across the instance.
You're right that there are lots of threads on this subject, I don't think you're going to find that the consensus has changed much because the functionality itself hasn't changed.
Grégoire Michel's Definitive Guide to Setting up the Unsubscribe Link is still a solid guide on setting this up from a linking & tokenising perspective - follow that and you shouldn't have any issues in that regard.
To the fields point, if you don't want unsubscribes from one workspace impacting mailability in another then there's no current workaround other than custom fields (at least, not that I know of, and if there is I'd love to hear it). You can either have everyone use the system unsubscribe with the understanding that unsubscribe from one = unsubscribe from all, or you can create custom unsubscribe fields for each brand with the understanding that custom "unsubscribe" fields are just custom fields with "unsubscribe" in the name - they do not function like the system unsubscribe field, aren't auto-suppressed from campaigns, don't show in unsubscribe reporting, etc.
Whether you have multiple partitions or not may factor into your decisioning here.
You may want to upvote these ideas...
I personally have multiple workspaces, shared partition, with each workspace effectively split by brand. We have custom unsubscribe programs for each brand, with each brand using a set of custom unsubscribe (and opt in) fields.
Hope that helps.
The workspace is where you store your assets.
The partition is where you store your data on a person, including whether they are unsubscribed or not.
You can have someone exist in more than one partition (as a duplicate), and this record could have a field value 'unsubscribed = true' whilst their duplicate record is 'unsubscribed = false'.
But.. Marketo has a feature called Durable Unsubscribe, and the fact one of the records is unsubscribed will also automatically unsubscribe all other records.
So strictly speaking, when discussing the Unsubscribed field, the answer is no, you can't have separate unsubscribe settings for each product/workspace.
But you can certainly implement a preferences centre type setup / custom fields to manage this - you'll just need to include these when you build your smart campaigns.
Here's one potential solution to consider:
This approach uses unique landing pages per workspace to add users to a static unsubscribed list per workspace.
User clicks on unsub link in email to arrive at landing page (LP-OptOut-Workspace-Confirm). When link is clicked, a smart campaign (Process OptOut Workspace) adds user to a static list (Workspace-Opt-Out-List).
Each Workspace has unique opt out landing page
Each program or email shares same link to opt out page for Workspace
Email Programs must include Smart List with Member of List filter in order to exclude opt-outs from delivery
Elements Required Per Workspace
Operational Program: OP-Unsub-Workspace
Landing Page: LP-OptOut-Workspace-Confirm
Smart Campaign: Process OptOut Workspace
Trigger: Clicks Link in Email (Email: is any, Link: is http://...)
Flow: Add to List (Workspace-Opt-Out-List)
Static List: Workspace-Opt-Out-List
Usage of Workspace-Opt-Out-List:
Any email program sent from this workspace must include a Smart List filter specific to the Workspace: Member of List, not in OP-Unsub-Workspace.Workspace-Opt-Out-List