I've been reading many threads debating about link diversity and social signals as the new direction for SEO, post-penguin. I recently watched a vid from TED presented by a youtube employee about how videos go viral on youtube, which broke down to 1) trendsetter/celeb endorsement 2) shock/surprise and 3) audience participation. Considering google's understanding of the viral process, i'm taking an educated guess that a link must not only be drip-fed to simulate natural growth, but the pattern must flow from a high ranking source(s) down to low ranking sources. I assume this is the purpose of a link pyramid? But factoring in the necessity of social signals, I also guess that their implementation must appear natural as well? In other words, High PR Sites publish links < social signals from the High PR sites' fanbases are generated (and at the same time) High PR Sites publish links < Lower PR Sites Link to High PR Sites < social signals from the lower pr sites' fanbases are generated and so on . . . I just wondering if this might possibly be a key to natural linkbuilding now that social signals carry weight in SEO. Any thoughts? And an added thought . . . if there is a sudden shift in the search volume of a keyword on google/youtube, might that also signal that offline media (radio/tv) has triggered people to suddenly search for a term, which google may factor in a correlation between new links and social signals?