Some sites (like deviantArt) do successfully upsell to premium accounts, where one of the many features is no more ads. (And they actually advertise "no more ads!" to encourage upsells, though they advertise other features too.) Only a tiny portion of internet users have heard of adblock let alone use it, sadly (or perhaps not sadly if you think ad-driven companies like Google have made a lasting positive effect on the world), and even if they've heard of it forking over a credit card number may be conceptually easier than installing an addon or calling their "computer whiz nephew" to come over and do it.
Anyway, one way Facebook could do this is by upselling to an account where you have access to a database table or key-value file (or mixed) showing you all the data they have about you (not necessarily use). They could further upsell you on using your data for a particular function or not using your data for a particular function, showing you the documentation to the various functions in question. e.g. an option called "Send to credit agencies" (which you can pay $5 to turn off) when expanded highlights the particular data or sections of the data it sends to which agencies. Indeed, there may even be code it can take the docs from:
/**
* Sends user's Account Data (username, full name, address if provided, etc.) and a credit score estimate determined by @See otherfunc to EquiFax.
*/
function send2equifax($account_data) { }
Or, you know, something simpler like how oAuth permissions are granted. But considering the likely target market for significant data restriction upsells, customers are probably pretty technical and can handle the specifics.