We all know that Google bases ranking on the quality of the content, and we all (SEO’s) argue about the rating system of that measure of quality, but today’s announcement {http://econsultancy.com/uk/blog/8213-google-starts-indexing-facebook-third-party-comments } might add a new dimension to this debate.
Google are indexing Facebook comments as well as standard blog comments and of course their plus1 data. I see this becoming the defacto signal for search engines rating content – i.e. content that users generate.
Here’s how it could look: