Social Media Optimization is now the best way to drive targeted traffic to a blog.With SMO you need not to worry about Google Animal updates,which will kill your blog .
Facebook,twitter,pinterest,stumbleupon,reddit,digg,delicious,google+,scoopit etc are the best social sites which can drive massive traffic.
Only thing is you have to build user base/fan base for every social profile.
1)Add Social Sharing Button to blog post
2)Ask visitors to share the post if they liked it.