They get to make money off of you for the rest of your life. They'll sell ads to companies, and they'll sell your data to anyone willing to pay enough for it.
If really you want to see how people feel about being surveilled there's plenty of videos online showing people freaking out at someone just taking photos/video in public. A ton of people are absolutely convinced that the law protects them from being recorded in public. They're not going to imagine that a "respectable" corporation would be allowed to do it to them in their own homes.