Pardon my language but: no fucking shit. $20bil was unbelievably overpriced. This is the one major tech stock that I simply do not get . ~$125 a user is insane.
Facebook is >$200 per user.
FB has more immediate ways to expand too, most likely. We already saw them transition from relying on getting a cut of things like plugins and games in FB to that not mattering at all. They could try to go into payments more, maybe an Adsense alternative -- likely the only company capable of doing so too. Yahoo failed at doing it a decade ago and any other company has always been much more niche with much more worse payouts.