Google did not build glass to make 200 million dollars selling it; they built it to make another 10 billion on Ad sales. Said that, its not hard to imagine that Google will be extremely defensive in giving anyone, including FB extensive access to their Ad plate. If anything, this will be an extension into G+ and, if necessary Google will prevent this walled-garden in court.

Thinking "how much company would pay for that" does not get me excited either. It been proven over and over again (through different social networks) that just because my friends likes something, it doesnt mean I will like it either. It neither means I will be more reluctant to try it out. "Like" on its surface does not prove me much information, and most FB users know it by now. Example: if someone "likes" chick-fil-a, what does it means? Does it mean they prefer chicken over beef? Does it mean they love the company? Or simply they are an employee of said company and want to look good in case their employer peeks on their wall? Or maybe that they support c-f-a's Christian roots of not hiring gays? Or perhaps because they hate humanity at all and they love that c-f-a puts aluminium and MSG into their food? "Like" alone does not mean "yes go eat here and spend your money its worth it".