It took me almost exactly two years. I bought my first cig-a-like in December of 2011 and through trial, error and giving up for sometimes months at a time, I found what works for me. On December 12, 2013 I smoked the last cigarette I had and started vaping exclusively. I did slip up on days 5 and 16 but didn't let that worry me too much since up until that point I hadn't lasted 5 days straight, much less 16. I probably would have never tried the Kanger line if I hadn't read about it here so this site had a lot to do with my (and I'm sure a lot of others') success.
So happy you dropped the smokes. Yeah this is a super site. Endless information and help. Ain't been a month yet and I've already bought 2 Kanger evods, 2 evod clones, 5 Kanger T3S's and 2 Kanger Unitank minis. Diy' in and makin good juice except for the Tobacco flavors. I'm learnin a lot about diy here. Great site