I'd rephrase this: "Social is the more general form of PageRank". If you think about PageRank in it's original form, it harnessed a social signal (linking to a

I'd rephrase this: "Social is the more general form of PageRank". If you think about PageRank in it's original form, it harnessed a social signal (linking to a site) to provide better search results. Degrees of pages in the graph-of-all-pages are easily-machine-readable manifestations of social signals.