Personally, I guess I would take issue with the description of these services as being free. I think that the archiving and monitoring of information that's provided by users is what provides the monetary benefit to the companies. I would shudder to think of what the value of the database collected by a lot of these social media companies is, because that's where the real value is.
I also think it's a little different if consent has been given and a consumer explicitly requests, let's say, advertising for a new Ford pickup. It's an entirely different matter, I think, when a user types something into their update panel that talks about memories they had when they were young that concern good memories of riding around in a Ford pickup truck, and then all of a sudden advertising for the Ford pickup truck is tailored toward that user response. I think there's a distinction that should be drawn there.
The monitoring is what provides the monetary value, so I don't necessarily agree that it's a free service, but I can see the position being put forward.