Facebook and other social networking websites are useful for SEO up to certain extent. You can create page for your business or product and advertise it by sharing the link of that page. Plus you can add images, videos, Audios, links to images, RSS feed and much more on your page to make it more useful for your fans. This helps a lot inincreasing traffic to your website thru Facebook.
Face book just like news any body have new so that person can share with on his status all us friends... well face book is very valuable for seo because we would have do like our website new page. So it will be very benefits . Because new page have come more and more visitor so it is good point of view from search engine.