Smoking is addictive. However, it is also very easy to stop.
Governments want to reduce smoking in public (I see Bangladesh has become the latest country to ban smoking in public) but they are not providing the best method with which to give up. In the UK a packet of cigarettes comes with a monochrome health warning in large letters citing some of the things that smoking can cause. I believe that in Canada the health warnings are replaced with actual photographs of ailments caused by smoking.
Every smoker wants to stop. Ask a smoker if, before that first cigarette, they would take the other option and not smoke it. They will respond in the affirmative. Any one who replies in the negative is either joking or deceiving themself.
A recommended method to aid stopping smoking is to use nicotine replacement therapy such as chewing gum or patches. The big problem here is that smokers are addicted to nicotine. Buying gum or patches only serves to continue the addiction. Gum and patches, however, are more expensive than cigarettes. So nicotine replacement therapy is harder on your pocket than smoking. And companies know their product is addictive - it's the whole idea of nicotine replacement therapy.
Now, here's a strange statement. Smokers don't actually realise they are smoking. They put the cigarette in their mouth and puff away on it but they don't consciously inhale and analyse (via taste and smell) what they are doing. It is solely an action that they do. If they were to consciously light a cigarette, inhale the smoke, and think about what they were doing they would be disgusted.
A common way of stopping is to pick a date and then stop. These people start counting the days and it is only a matter of time before they break mentally and return to feed their addiction.
The common phrase used, with regard to smoking, is 'giving up' which smokers think they are doing when they stop smoking. The problem here is that by 'giving up' there is a psychological feeling of making a sacrifice which is tricking the mind (and smoking is all about the mind) into thinking they are making a big sacrifice by stopping smoking. In fact, they are not making a sacrifice. They didn't smoke before so why would they be giving it up. All they need to do is stop; not 'give up'.
An ex-smoker doesn't feel nicotine leave their body. The withdrawal symptons are painless. All the 'Oh! I need a cigarette' talk spouted by 'quitters' is purely in the mind.
The other common phrase used is 'habit'. Smoking is not a habit no matter how you look at it. Smoking is an addiction. A smoker is an addict. Pure and simple.
So, Martin, your friend is one of the worst smokers (and addicts) around. While the person who smokes 20...30...40...n per day knows they are addicted and either lacks the motivation to stop or doesn't want to stop yet the person who is the 'casual smoker' believes they can stop anytime. But they never do stop. Their nicotine dependency is apparent. They are addicts. They are fooling themselves.
But, when it comes to getting people to stop. The approach is all wrong - by healthcare units, health boards, etc. They constantly spout the benefits of non-smoking, the contents of a cigarette, the grim facts about how smoking takes time off your life but tell these facts to a smoker and they'll light up in front of you and, depending on their level of defiance, blow a puff of smoke in your face.
A smoker has to want to stop. Every smoker wants to stop. Every smoker has the potential to realise they can stop anytime. Every smoker can stop anytime.
They have to do it all by themselves though.
They go so well with coffee. I love to read at coffee shops and smoke while I do so. 
