Earlier quoted context omitted.
This is why social media ToS are typically concise and clear: "License agreement: We spy on you and sell your information to anyone that's interested, press accept to continue".
Say I want to buy information about you. How would I go about doing that? Where to I put in my credit card details? Facebook doesn't sell data. They sell advertising space. They're a billboard company.
Just at a cursory evaluation, it makes no sense, because if Facebook sold the data directly, why would advertisers even need Facebook after that? All of those questions can be answered by simply playing around with FB Advertising UI for less than an hour. But hating on FB is fashionable now, regardless of whether the reasons are justified or not. Given how there are plenty of legitimate issues with Faceebook, it really annoys me when people throw around these types of questionable accusations against FB without even looking into the subject matter first, because it just weakens legitimate criticism of FB.
Back to the topic at hand, you are totally on point about the billboard analogy. If you are a business, you don't go to Facebook and say "give me the data of these users", you say, for example, "here is my ad, show it to users who are in this geographic area Z between ages X and Y who are into surfing and indie music". And then you get to see stats about interaction of those users with your ad, like "users who are closer to age X than age Y are more likely to click on your ad", so you draw a conclusion that your ad doesn't seem to appeal as much to the upper boundary of your target age range, maybe you need to tweak the ad or split it into 2 separate ads (one for users between ages X and (X+Y)/2, and another for ages between (X+Y)/2 and Y). At no point you get any additional info on the users, and neither do you get any individual user info, just anonymized aggregates.