looks like facebook is trying to envelop more and more services. the group-buying model is so easily duplicated that there is no advantage in simply entering it. Facebook needs to create an edge to differentiate itself from the hundreds of group-buying website. One way is to markets itself as an all-in-one social media platform (whereby friends could easily "suggest" deals for you and you could look at which friend has bought the deals)- making group buying even more of a social experience.