And every time, they gladly acknowledge that I will not receive any more messages of that kind.
"Okay, you won't get any more mails about new messages from friends. Okay, you won't get any more mails about stuff your friends liked. Okay, you won't get any more mails about stuff some other random people liked. Okay, you won't get any more mails about new stuff posted in groups you joined. Okay, you won't get any more mails about new stuff posted in groups you did not join, but we think you might be interested in. Okay, you won't get any more mails about new photos posted by your friends. Okay, you won't get any more mails about new photos of cats posted on Facebook. Okay, you won't get any more mails about news articles with dogs in the title. Okay, you won't get any more mails about postings your friends liked that complain about the weather and were written by women of age 35-40."
Okay, admittedly the last three were exagerrated, but all the categories before have been actual "notification categories" that I successfully opted out of, before I put a generic Facebook email filter in my mailbox, because apparently nothing else is able to stop their overly-specific-category-generation-engine from spewing out new categories to keep me busy opting out of.
So any service that feels slightly abusive gets its own email like that, and then ignored usually.