I have zero sympathy for these people. My spouse for example often gets added to mailing lists when purchasing a product (just like we all do). Instead of click

I have zero sympathy for these people. My spouse for example often gets added to mailing lists when purchasing a product (just like we all do). Instead of clicking the unsubscribe link, they'll just "open" the email without reading it to mark it as read in their inbox, and immediately go on to the next one. These are essentially spam that my spouse is too lazy to mark as such. I have to wonder how many of the "opens" the author's lists get are just like this. "Oh, that stupid list I got subscribed to somehow. Mark as read." I have a very deep suspicion that they're mailings are essentially spam to a lot of people who receive them and this is correct classification by Google.