...A user asked Cutts how algorithms parse the differences between popularity (high pageview totals) and actual subject matter authority. The question was framed in the context of social media: If social signals affect search algorithms, does Google trust the traffic coming from Facebook or Twitter as an indicator of expertise?

The video response was, while it’s a work in progress, search crawlers are getting better at assessing credibility. One of the ways they do this is the old reliable method – links. However, they don’t bestwo authority in a vacuum. Basically,  a website with a lot of inbound links from relevant (and well-known) sites will build authority on that topic.

A website with a lot of inbound links from relevant (and well-known) sites will build authority on that topic.

This is a call for subject-matter consistency. If a business reliably provides resources and valuable information about a certain topic, it will accumulate inbound links that contribute to page authority....

Via Jeff Domansky