I'm using Long Tail Keyword but not receiving traffic

Hi
My site is 3 months old Total 49 Posts, from last month i am writing a post for day
6 posts of them are having long tail keyword with low competition and max 500 searches but i don't get any organic visitor.
I always write posts with 400-500 word,
With how much Long tail keyword posts can i get traffic and Example When i write a post should I copy the link and to comment in high websites or only domain.com
Thank You WordPress ...