Backlinks are only part of the Google algorithm, so why should it be possible to explain greater brand prominence by backlinks alone?
Question: If "offline brand authority" were a factor, how would Google implement it? The idea of employees typing a list of brand names and assigning authority value to each doesn't sound very Google-y. The other possibility--online mentions, as opposed to online links--seems more likely. But why limit it to "social media"? Why not news media, Wikipedia, and Web sites in general? Surely frequent juxtaposition of keywords like "Dell" and "laptop" at cnet.com or "Hostess" and "cupcake" at nytimes.com ought to provide at least as much brand authority as juxtaposition of those keywords at Facebook or on Twitter.