If you're running a mail newsletter, this tracking is pretty important. You're supposed to stop sending emails to someone who's not interacting with them, or you get an extra point towards being flagged as spam. Since people are already weary of clicking the unsubscribe link and instead casually mark everything as spam, every little bit towards keeping your reputation counts. It's a damned if you do, damned if you don't situation.
This is the reason why I had to implement a tracking pixel on https://hndigest.com
Tangentially related anecdote: I also had to implement redirects instead of direct linking to the stories: At one point a URL with the .tk TLD was at the top of HN, and as soon as I sent out the first email with that story in it, my email sending service immediately flagged my account as a spammer and blocked all my sending, because the .tk domain was such a red flag. Since then I redirect all stories through my own domain, to avoid any other TLD red-flags from crippling the service.
It's difficult running a legit DIY newsletter, every party involved is super suspicious and one wrong move or mistake can end it all.
Edit: A lot of people are wondering about why I think people press the spam button instead of unsubscribe, so let me elaborate a little more. HNDigest uses double opt-in (you receive a confirmation email which you need to click on before you're subscribed), listens to all feedback loops, has an instant unsubscribe button. We never spam or send emails that weren't requested by the user. By all accounts, it's a legit newsletter and I try to be as above board as possible.
Yet 30% of all unsubscribes happen because someone has marked the email as spam. I know this because this generates a notification on the feedback loop, and then I immediately stop sending of course. These are the facts. So, assuming HNdigest is not actually spamming (which is something I do believe), 1 out of 3 people click the spam button either by accident, or to unsubscribe.
This is the reason why I had to implement a tracking pixel on https://hndigest.com
Tangentially related anecdote: I also had to implement redirects instead of direct linking to the stories: At one point a URL with the .tk TLD was at the top of HN, and as soon as I sent out the first email with that story in it, my email sending service immediately flagged my account as a spammer and blocked all my sending, because the .tk domain was such a red flag. Since then I redirect all stories through my own domain, to avoid any other TLD red-flags from crippling the service.
It's difficult running a legit DIY newsletter, every party involved is super suspicious and one wrong move or mistake can end it all.
Edit: A lot of people are wondering about why I think people press the spam button instead of unsubscribe, so let me elaborate a little more. HNDigest uses double opt-in (you receive a confirmation email which you need to click on before you're subscribed), listens to all feedback loops, has an instant unsubscribe button. We never spam or send emails that weren't requested by the user. By all accounts, it's a legit newsletter and I try to be as above board as possible.
Yet 30% of all unsubscribes happen because someone has marked the email as spam. I know this because this generates a notification on the feedback loop, and then I immediately stop sending of course. These are the facts. So, assuming HNdigest is not actually spamming (which is something I do believe), 1 out of 3 people click the spam button either by accident, or to unsubscribe.