Ask HN: Why does it take "up to x days" to unsubscribe?

[basicallydan]

A lot of websites have newsletters or mailing lists, a lot of them are managed by internal systems and many are external.

Sometimes, regardless of whether it seems to be internal or external, when I unsubscribe from a newsletter I'll be told that my request will take "between 2 and 5 days" or "up to 48 hours" to be processed.

Why is this? Surely it's just a matter of deleting an email address from a table. Is it a ploy to keep me subscribing, in the hope that those 48 hours will be enough time for me to realise the mistake that I've made?

[kevinconroy]

It may be a matter of delayed syncing for certain websites with multiple legacy systems that aren't tightly integrate.

What I think is more likely, though, is that they are using a fairly sophisticated email service which is capable of generating millions of emails and queuing them up in advanced of a scheduled delivery date.

Say you had 10 Million subscribers that you wanted to email a coupon or offer to that was only good for the next 24 hours (e.g. "Saturday's 1 Day Sale"). In order to get those into 10 Million inboxes within a 10 minute window you need to pre-process as much as possible. The email marketing person schedules emails to go out at a certain time, they are generated and queued, and then pushed out in bulk. Checking if you've unsubscribed is most efficiently done when generating the emails to be queued, not when going to send.

So when you go to unsubscribe, they might have an email or two in the queue ready to go to you. It's much easier to say it will take 48 hours for your unsubscribe request to go through than it is to explain that "you're unsubscribed, but we might have a few emails in our pending queue that would be a pain for us to delete or prevent from going out, so please just forgive us during this period."

(Side note: There's a surprising amount of interesting tech going on in some, but not all, email marketing programs.)

[stevencorona]

I used to work at a "very large email advertising company". We would take another companies email list and advertise to it, splitting the profit with the company that owned the data.

When an unsubscribe came in- sure, we could remove it from our own list, but we'd still have to give the unsubs to the original data owner, who'd need to then send the unsubs to any other companies that were using their data. And that's at the simplest, it can run multiple levels deep (i.e, Company A sells data to Company B who sells data to Company C).

Another reason is that "targeting" emails on a user-by-user basis can take lots of processing time, too much to be done in real-time when the email is being sent out, so they are often queued up several days in advance.

[Zenst]

If everything runs on one system in one location then yes your right. They don't and in that changes are propergated periodicaly. By saying it will take upto X days covers them on this front and in that protects there liability.

Also note that they don't do them instantly to prevent forms of account denial of service attacks by having bots create and delete accounts instantly.

But if you run your own mail server then you can just instantly add those email senders to your bounce list and get a much better effect.

[PonyGumbo]

>Surely it's just a matter of deleting an email address from a table.

Actually, they have to add you to an opt-out table. If they just delete you, there's the chance that you'll get re-added at a later date.