I have 10 facebook backlinks and 40 shares....my serp is good comparison to other sites. I think facebook,twitter is a good opportunity to make your website good in search engine.
Facebook can give you traffic but the links are of no follow attribute so you can earn an amount of traffic but not ranking if you have only these as your back link.
Social Media like Facebook and Twitter are able to provide you with a huge amount of traffic. However, they won't be counted as backlinks even though you promoted your URL through Facebook and Twitter.
Its true. you get good SERP after adding y our business on Facebook,. specially when you update your profile by adding your product or new offer.
Only using social media back link will not give you a good ranking. It will provide you much popularity, promotion and traffic. But for getting good rank, you must have to develop some good quality back link.
Google considers all social networking signals for better SERP's since the importance of Social Media has grown tremendously over the last few months.
I am dis agree that Facebook will give you backlinks because it is a nofollow links. Facebook will only help you to increase the traffic of your site.
They can give you traffic by discovery of your site through FB. As for backlinks, I believe FB has nofollow links.