I had a 30 cigarette a day habit for 50 years. Managed to quit for a 3 year stretch. Found myself in an extremely stressful situation and started back. I turned to e-cigs when I was diagnosed with COPD at age 66. I tried several brands, finally settling on Green Smoke which provided a very real simulation of cigarette smoking. I was tobacco free within 2 months and have been ever since, a total of 3 years. At each of my checkups, my doctor has informed me that my condition has not advanced. I give my e-cigs credit for that. My wife and son started with e-gigs about a year after I did. We now have a smoke-free home. No unpleasant smell, no tobacco stains on our walls or belongings. Its fantastic. Most importantly, e-cigs have extended my life expectancy. My doctor agrees. Why else would my COPD remain in check for 3 years???!!!