It's my understanding that unsubs don't count against your Marketo limit (as you will not be marketing to them), but I could be wrong. To that effect, I just stockpile them to make sure they never get emailed and move on. If they ever contact us, we re-sub them, but as you say, it doesn't happen very often. It's probably safe to delete them after 2-3 years of unsubscription, as they are probably no longer valid by that time, and/or have forgotten about you.
It sounds like you have some sort of team who is feeding you a lot of bad prospects. If you delete your list of unsubscribes, it is likely those names will find their way back into your database and you run the risk of becoming classified as a spammer, especially if you keep sending to people who have unsubscribed. They take up extra room, but they are your insurance against something worse and that's damaging your sender reputation. That potentially affects all Marketo users as well.
A better approach may be to focus on better content and/or becoming ruthless with the quality of your lists.
Unsubscribes do count against your limit.
Mike is correct in his statements.
I've written about this before. It highly depends on what you are doing with the leads overall. At one firm, it was totally possible that an unsubscriber of any type could become an MQL through their website usage and campaign responses. So I'd never delete anyone just for unsubbing.
As Mike noted, it is usually good to keep the unsubscribers as long as reasonable so that you have a solid suppression list and don't get blacklisted. It is your responsibility to honor the person's original request until they change their mind.
You should also create a multi-channel subscription management system so you can reduce total unsubs. People will sign up for at least one item of interest if you offer them 4-6 options.
That being said, I think it is safe to wait 12-18mos and do this:
-No Website Activity/sign ups, etc
then Delete Lead in Marketo ( and maybe SFDC, unless there are recordkeeping/data issues).
Losing a large list seems scary, but there is significant upside to gaining permission.
I would take a small but significant sample (5000 records) who haven't opted in or out, and send them an email asking them to opt in to continue receiving emails. If they don't respond, suspend marketing to them. If they do respond, track this as a program.
What you'll likely find is the number of opt-ins is small (10%) but their engagement in the future far outpaces those who never opted in. This is the kind of data that can demonstrate a business value in using opt-ins rather than spamming everyone.
My understading was also that unsubscribes DON'T count for your "marketable database" # by which Marketo charges customers.1 of 1 people found this helpful
It's a bad idea to ever delete unsubscribes - in fact this is one list that I would recommend you keep forever lest you risk emailing someone on that list again, and getting in trouble with CAN SPAM.
Also just because someone unsubscribed from your email list doesn't mean that you can't call them, or that they might not come back to your website and express interest in the future.