1) it's addictive(obvious enough)
2) It means that you can have numerous short breaks throughout the day.
3) There is nothing better than a cigarette after a coffee or tea,everytime you have a cup of tea you will want a cigarette
4) At bars it is usually alot more social in the smoking area as you can hear what people are saying.
5) Smoking can often be a good way to meet new people, asking for a lighter off someone in a smoking area can sometimes lead to further conversation
6) smoking means dickheads that dont like smokers wont talk to you.

Have you ever tried to quit? I am finding it very difficult as you can see.