Integrate Facebook and Google+ – Take the time to integrate social media, including Linkedin, and Twitter into your site. Provide more options to share content and get people talking about your site. Google will consider how popular your brand or website is with social media sites and bump your ranking over similar sites with smaller social media footprints
*BONUS* Google+ is extremely helpful in providing extra information on to search pages. Now that Google integrates Google+ pages into search results, you can increase your presense significantly. Check out this comprehensive guide by AJ Kohn for how to take advantage of all of Google+’s SEO abilities.