I think that such an advertising network would run into problems, since developers who integrated with it would be violating the Facebook Platform Policies: Yo

I think that such an advertising network would run into problems, since developers who integrated with it would be violating the Facebook Platform Policies: You will not directly or indirectly transfer any data you receive from us, including user data or Facebook User IDs, to (or use such data in connection with) any ad network, ad exchange, data broker, or other advertising or monetization related toolset, even if a user consents to such transfer or use.