When I started vaping, I was using nicotine mixes around 24mg and did not vape constantly.  As vaping grew on me (finding great flavors) I started vaping more - but began to get headaches and the shakes from too much nic.  Since discovering tastyvapor doublers (flavored zero nic fluids) and DIYFlavorshack zero nic juices, I have been able to reduce the nic levels to a point that allows me to vape for pleasure without getting too much nicotine (and the associated nasty symptoms).  I cut the 24mg juice with zero nic to probably be around 6mg or less. 
 
I may go through 10 to 15ml through my cartomizers in my eGo in a week.  I was a pipe smoker who was running through a pound of specialty tobacco every two weeks.  This is more cost effective, definitely less damaging to my mouth, lungs, and clothes, and I can do it pretty much anywhere. 
 
I did not start vaping to quit smoking.  I was looking to reduce costs of a habit I really enjoy (especially due to tax increases on tobacco) and vaping using an eGo meets that need for me.