I was wondering about this. I saw someone smoking yesterday and realised I don't think that I know anyone who does.
When I was growing up though it was really common. My mum smoked 20+ a day until I was about 10 when she decided to give up. My dad smoked until I was nearly 20 (and probably carried on in secret!!)
People must smoke or they'd not be for sale and I'd not keep seeing cigarette butts on the pavement but how common is it now? Also they seem to cost a fortune - about £10 a pack - that must really add up for heavy smokers.