the double face of facebook's value exchange and the value of a purposeful social space

the value exchange of facebook has two sides. 

the first is the business side. in exchange for money facebook gives companies the opportunity to address a specific segment of its users. extensive  user profiles based upon the digital behaviour within the facebook (connected) domain combined with algorithms help companies to precisely reach their targeted audience. 

the other side of the exchange is related to the users. facebook provides without any monetary cost their users a platform to connect and interact with what is called their friends. and it is very much used by over a billion people. in exchange facebook is allowed to collect and use all the digital traces of their on-line behaviour as far as it is part of the facebook's sphere. 

the more ubiquitous and the more broadly and intensely this platform is used, the more value it has for the advertisers and the more revenues Facebook can earn. the individual user is as such not directly involved in this value exchange with the advertiser, although he is a profound contributor of value.

in terms of a purposefull social space where there is an open, balanced and well understood exchange of value for all participants, the question is whether this is the case with facebook. or is facebook better named janus-faced book?