In your typical cigarette, here’s how tar and nicotine work together:
Tar provides the taste/flavor and the harmful (cancer-causing) elements;
Nicotine provides the addictive element and acts as a mild stimulant
Take out the tars, and what you have left is nicotine: highly addictive, but otherwise a harmless mild stimulant.
When nicotine gums and patches first came out, you could only obtain them by prescription: Nicotine is so highly addictive that everyone assumed it must be harmful as well.
But now nicotine can be obtained OTC and is pretty much uncontrolled (I think you have to be 18 years old to buy it). Health authorities still don’t want kids to get hold of it because of its high addictiveness and expense; but as of five years ago when I last checked, long-term medical studies showed that nicotine use alone didn’t result in any harmful health effects.
So some people go ahead and chew the gum for its quick stimulant effect. It gives a noticeable boost like a little cup of coffee. But it’s kind of expensive, and like any addictive drug you have to wean yourself off it gradually if you decide that you're tired of paying for such a habit.
As for me: It was great for getting off cigarettes. When I used it in place of cigarettes, I missed the flavor of cigarettes, but my health improved instantly since I wasn’t clogging my lungs with tar. Meantime I didn’t experience any withdrawal symptoms from the lack of cigarettes since I could have all the nicotine I wanted via the gum.
Five years later I was still perfectly healthy with the gum, but I knew that I really didn’t need such an expensive habit anymore. So I took about a year and weaned myself off the gum slowly. I chewed nicotine gums at specific times of the day, and then every few weeks I would knock out one gum-chewing session or substitute cinnamon gum for the nicotine gum.
These days I’m still prone to chew on a toothpick occasionally. And cigarettes still smell good to me when I pass a smoker. Sometimes I just want to be near a lit cigarette and enjoy the scent and the memories. But cigarettes (and gum) just aren’t part of my self-picture anymore; I couldn’t seriously imagine picking a cigarette up and lighting it and returning to all the negative burdens that come with those things.