When i first started there were hardly any visitors. However, I started to post regular articles and then slowly started to get picked up from google. Topics and keywords were selected from "google search hints", but then the promotion via twitter and reddit helped to gain some growth in traffic.
I just started a newsletter https://pythonhowtoprogram.com/newsletter/ but I have very little signups so far. Still need to work on converting those casual visitors in to signups! My next milestone will be either 5000 monthly traffic or 50 email sign ups!