You can use facebook to get only organic traffic. Because it is nofollow site of course it wont help to boost your keywords but you can improve visitors of your site through facebook.
---- by now many of us know about twitter and Facebook - from the two websites named the most popular social network marketing online Internet application in the history since the birth of the Internet in 1992. One thing we must consider, when using Facebook.com you need to apply it needs and necessities that are commonly known as connecting your ping services from your blogging applications that interact directly imprinting impressions from your blog post on to Facebook.com and twitter.com........................... Bruce Clay said it in one of his blog posts," you can get 240 page views just by updating your website's with Facebook and twitter --- while that's free traffic..................... Something a webmaster search engine optimize can highly consider
I agree with you through social networking websites you can get huge traffic but less effect on ranking your keyword.
also bear in mind --- when it comes to social media you can grab clients looking for your products and services ----- in these days and times you need to be able to get targeted traffic ---------------- try building a Facebook account with the keywords connected to your website or blog marketing franchise Corporation and connected to your blog media application..........................
Yes it will generate good number of traffic also it create brand awareness of product, but it will not increase keyword ranking.