Once in a while, junk email may make it to your email inbox, though, and — lo and behold — it contains an "unsubscribe" link. Or is it a purported "unsubscribe" link?
A Wasted Effort?
Generally, the content of spam is not to be believed, and that applies to all promises to take you off the list as well. From that avenue, unsubscribing from spam is wasted effort better to be spared elsewhere.
What Could Happen if You "Unsubscribe"?
Then, of course, you're already getting the spam. If you follow the unsubscription instructions that are easy to follow, you can be taken off one spammer's list — or at least you're not off much worse. (Take care not to be tricked into giving away any data other than your email address.)
Be Nice to Newsletters You Don't Like (Any Longer)
Finally, there's the chance that what you not think is spam looked like a nice newsletter to sign up for seven years ago. If you use the unsubscription method offered instead of reporting the email as junk, you spare the publisher and your email provider a lot of hassle, and you make spam filtering much more effective.