i prefer twitter rather than facebook, its my self experience for my sites when i used to promote on facebook and twitter both and no doubt twitter rocks on my site traffic and ranking.
I have a blogsite today and I share it on Social Media like Facebook, Google+, Twitter and Pinterests, however, my views or the unique views are less and I don't know how to make my blog more visible online. I think somehow Social Networks are helping my blogs to be seen.
I have a Twitter profile and Facebook for my sites. I used to automatically share to them whenever I published a new post. But things changed when Jetpack updated and rolled out new features. Now I am sharing manually but it needs time. For traffic, yes I get some traffic from the said pages linked to my blog.