1 out of 3 people who smoke will die from tobacco cigarettes. It is one of the main leading causes of preventable carcinogen deaths in the United States. They're not biodegradable, they pollute the environment, they cause second hand smoke, and physically ruins your health substantially.
Electronic cigarettes could be the healthy alternative to smoking: They're battery powered, when you inhale you exhale water vapor, they're 10 times cheaper than regular cigarettes, e cigarettes only have a measurable amount of nicotine without all of the harmfull chemicals in traditional cigarettes, and environmentally friendly.
(Nicotine in itself is a stimulent. It's about as bad for you as a cup of coffee)