SEO experts have spent the last decade preaching a gospel of optimized page-level elements and inbound links. Those things are still important today,but getting real SEO results these days requires not only a technically optimized website and relevant inbound links but also a strong, vibrant Web presence that supports your overall brand. Which is where social media comes in.
Promote your content at sites like Facebook and Twitter. Search engines use shares and tweets as a factor when ranking content—so be sure to publish your most recent how-to articles and blog posts where readers can express their approval.
Interact with your fans and followers. You can't just dump content in social networks and expect it to go anywhere. If you don't have many engaged followers on these social media sites,there won't be anyone to help promote your content via shares and re-tweets.
He also suggests driving engagement with tactics like these:
Use keyword research to drive content development. The keywords that visitors use to find your site provide a good indication of the content they want to read. "Look for areas of high search volume, and develop content around those subjects,"
Use historical keyword data to exploit seasonal trends. For example a client's traffic spiked on the term "motorcycle safety" in May. After discovering May was Motorcycle Safety Awareness Month, we prepared content ahead of time so it would rank well during that period.
The Po!nt: Socialize to optimize. Social media matters to search engines—and that means it matters to you.