I Just Got a Cool Breez Electronic Cigarette. How Often Do You Smoke Them? is It Like Smoking a Real Cigarette?

I just got this e-cig. I have been smoking it for a week and have not had a single cigarette. I am just wondering if I should smoke it for like 5 minutes how I used to smoke or just hit it periodically throughout the day? Either way I like it and enjoy not smelling like smokes.

Suggestion:

I have a friend you uses those exact ones and he only does it when he has an urge to smoke, so its periodically.