"Facebook will market you your future before you’ve even gotten there, they’ll use predictive algorithms to figure out what’s your likely future and then try to make that even more likely. They’ll get better at programming you – they’ll reduce your spontaneity. And they can use your face and name to advertise through you, that’s what you’ve agreed to."
The order in which you are presented with items in your feed, which likes by which friends you see, your previous actions (most of which you cannot likely recall, but all of which facebook has a perfect memory), and many other details are not only used to advertise to you - they're used to build you into the type of person that will be more susceptible to advertising in the future.
Molding and shaping opinion and personality is nothing new, but it has never been this precise, this interactive, and this pervasive. The stimulus, response, and reward loop has never been tighter. Those who use these services are being trained to exhibit particular valuable traits and behaviors, and the level of control over these manipulations will only improve as data is collected and algorithms are refined.
If you've been using a service like Facebook for several years, they know who you have been at each point in time. Imagine you've traversed states A, B, and C and are predicted to be moving toward D. If state F or Z is more valuable (and can be arrived at from state D), then perhaps through several months of training you can be led to it instead. If you're not continually aware of each small nudge in a particular direction, then your mind is absorbing and adjusting to these changes without you knowing about it.
I'd love to read more about this, and am sort of morbidly fascinated by the methods by which these mechanisms operate, and just how powerful these types of control can get.