The links comes from the social networking site are referral links it only brings traffic towards the website doesn't contribute in ranking the keywords related to the website niche

Links from SMO is one of the do follow links and improve website traffic rank and keyword ranking in google search.

I think it is very useful to us i am saying this because i already try to this it is really very good.

its can make traffic to your site but not all. Many way to get traffic to your site.

Social Networking helps to Build Link are:
Generating traffic in to the website
Building Backlinks
Promotion of products and services of the Business through Social Media Sites
The Best and Popular Social Networking Sites are:
Facebook
Google+
Youtube
Pinterest
Twitter
Tumblr

You should not rely entirely on Social Media Traffic. Organic is much better.

enables more natural backlinks in google eyes.
help you increase traffic

When you will go for website promotion then you can link your website with social networking sites this work will help you to good web promotion on Internet So this is the thing social networking links are helpful.

Links from social networking sites is more beneficial for you because its not only help you to create the backlinks but it helps you to maintain your status on the social networking sites.