it is expected that details on New content sharing button will be disclosed officially at facebook's annual F8 conference in San Francisco, this Wednesday.Content sharing button enables you to share your favourite websites into your pages but it also declared by the facebook that this website details will not be used for anaysing the market as well as for advertisement purposes.
Facebook also clarifies that they will not track the web behaviour of the users and also clearly stated that it will just use the age and gender details as specified in the initial profile of the user
Facebook's latest plan is to become more or less like a social networking site and hence it is also having plans to bring in more features which will be released soon in the F8 conference