Facebook created a currency called "Facebook Credits", which they hoped would be used to purchase apps etc., but it was discontinued. I guess they have put some thought into it, as any massive corporation with that much investor $$ to work with .. they think about EVERYTHING! Now that they see a working model, in a social media context, I believe they are doing much more than thinking about it, behind the scenes. I believe if this was acquirable, offers would already have been made.