That's not the point, it's not even necessary to use message content. All it takes is the other person looking up the subject somewhere. It's the same with devices supposedly listening in on conversations, there are far simpler and cheaper ways for advertisers to get the same data.

its facebook....assuming anything but the worst handling of user data is beyond foolish

This comment actually is a symptom of another problem. If you ask a random person if big ad tech should collect personal data in exchange for providing social media for free with ads, they would say no. But then immideately they would also walk into a Walgreens/CVS (pharmacies in the US) and the first thing they are asked at the cashier counter is their phone number and almost everyone just provides it with no second thought. Of course they get some loyalty member discount or whatever, but I don't now why they assume big retailer isn't sellimg the data / going to sell their data in the future. Perhaps just comes down to PR. If big ad tech is so bad and can't be trusted, wonder why no one assumes Google maps could sell your driving/over-speeding data to insurance companies? It's almost like we are told company a, b, c are bad, we haven't put more thought into it and are rejoiced seeing any negative headline about them. Nothing beyond.

In fact they've been doing it for over a decade

https://www.forbes.com/sites/kashmirhill/2012/02/16/how-targ...

You have every reason to believe FB uses message content to build and enhance your internal FB Profile, which is where ad targeting originates. To believe otherwise is just being gullible. If there is a profit enhancing mechanism lying on the floor, it will be picked up.

Op said "sent a message to a friend", it made no reference to facebook

Gmail famously scans the user emails to sell the info to third parties and sell adds

Ought be noted that while WhatsApp to my knowledgeable doesn't carry such a clause. It would be idiotic beyond belief to be led to believe that Facebook doesn't do the exact same thing

> Gmail famously scans the user emails to sell the info to third parties and sell adds

They don't: "We will not scan or read your Gmail messages to show you ads"

https://support.google.com/mail/answer/6603?hl=en#:~:text=Th....

Do you have evidence that they do? I think Google said they did this a long time ago, but they stopped since email content didn't actually improve revenue on those ads. Message data just isn't very helpful for ads, they would do it if it was useful but it isn't so they don't.

>> Gmail famously scans the user emails to sell the info to third parties and sell adds

Please stop repeating falsehoods.