And that was with algorithms that can't even begin to compare with today's AI capabilities. Meanwhile, fb uses all your phone's sensors to gage your emotional response to anything you see. How long do you linger on a post, do your eyes dilate, does your pulserate change, skin temp, do you react then undo it, do you start typing a response then delete it or alter it (yes, it logs what you type, even if you delete it or change it before hitting 'send.') Where were you when you interacted with it, etc etc. Then it feeds you content that will garner the reaction it wants.