I agree that the before mentioned companies most likely have a pretty good idea, but also that a lot of users cannot give informed consent to use your words. Wh

I agree that the before mentioned companies most likely have a pretty good idea, but also that a lot of users cannot give informed consent to use your words. When we go to a restaurant we can at least make a comparison based on experience; in the case of personal data we are rarely given access to data that allows us to build up any such intuition.