[ColinWright]

I use unique email addresses for everything, so I know where emails come from. More than once in the last two years I have unsubscribed from lists using the unsubscribe link, only then to have that email address received emails from new sources.

So for me, it does stand up to scrutiny, it still happens.

[peteretep]

I don’t think you’ve proved implication here though; as plausible an explanation is simply that the original source has sold your information on regardless?

[ColinWright]

It's the timing that makes it suspicious. It's exactly for this reason that I usually don't click the "unsubscribe" link for the first few emails I get. After all, if it's a one-off, why bother?

But I have scripts that count them, and when they get to five I then make the decision. Again, sometimes I continue simply to bin them, but sometimes I click the unsubscribe link. Mostly then they stop and there's no additional problem, but more than once that address has been used on other spam emails, and only after the unsubscribe.

Do you have actual evidence that it doesn't happen? You might, as others have, be arguing that it's not worth the spammers' effort. But setting up a script triggered by an unsubscribe is pretty trivial, and emails can then be sold at a premium, accompanied by a certificate of sorts that the address is valid.

So maybe it is worth their while.