Your site is very helpful. It's great that you want to collect some information so that you can weigh the options in your own mind.
People smoke for lots of different reasons.
Some do it because they think it looks cool. Some people like the feelings commonly associated with smoking - relaxation and stress relief. A lot of people, women especially, smoke because they think it will help them control their weight. Many continue to smoke cigarettes not because they want to, but because they're addicted and are having trouble quitting. But cigarettes are made with nicotine, a highly addictive substance.