Similarly to the way that inbound links are a measure of a website’s importance, social media participation has probably surpassed the importance of META tags as a way to judge the search relevancy of a particular website.
In a recent article by Danny Sullivan on Search Engine Land, Sullivan actually interviewed Google and Bing about the impact of social media on a site’s SEO and each acknowledged that social media was having an impact on how they calculated search results:
We do look at the social authority of a user. We look at how many people you follow, how many follow you, and this can add a little weight to a listing in regular search results. It carries much more weight in Bing Social Search, where tweets from more authoritative people will flow to the top when best match relevancy is used.
Yes, we do use it as a signal. It is used as a signal in our organic and news rankings. We also use it to enhance our news universal by marking how many people shared an article.
The same applied to public areas of Facebook, like your profile, but not to the posts on your Facebook Wall because they are behind the gated community and are are not indexed.
The bottom line: Participation in Social media is a worthwhile effort if it makes sense for your particular type of business. While I personally don’t think that Facebook is great for business to business efforts, business to consumer efforts on Facebook are having a temendously positive impact. But both of them (Twitter or Facebook) will have residual SEO value independent of the main benefits of enagagement, sharing, etc. And efforts like tweeting, posting videos on YouTube with fleshed out descriptions and keyword tags, as well as publishing fully-realized public profiles on LinkinIn are having a real impact on search results, too. If you haven’t gotten involved in social media marketing for your business yet, get started. If you are engaging in social media marketing efforts for your business, great. Do it even more!