gehrlekrona - 2:14 pm on Jun 30, 2012 (gmt 0)
What I tried to say in my last post was that I am sure Google is using user metrics and that more than we think they are. I think this is one of the reasons SERP's are changing all the time and that Google suggests keep changing all the time. Google can steer you into whatever they want to get metrics to evaluate and that in real-time. They don't need a Like button or G+ to see what pages people like or not, they can just use user metrics. Like soneone said, there is a lot of room for errors because they don't really know why someone didn't like a page so the results could be off.
In fact, I think that this is why Amazon, Wiki and other brands stick because they are "liked" by people. They go there and stay there.