The other posters have pretty much covered the relevant answer: people will smoke as long as they are allowed. Tobacco is a legal product; hell, you can buy a simple kit and grow your own if you want! And as #4 points out, everyone -- EVERYONE -- knows that smoking kills. However, everyone also knows someone who's smoked two packs a day for fifty years and shows no signs of illness... so we mask our scientific knowledge with anecdotal evidence when it confirms our bias. Raising taxes on cigarettes, thus causing the price to increase, doesn't seem to help. At this point, there's really nothing we can do except STOP SMOKING. If very few people are buying their product, the companies will increase their marketing for a while, and then focus on other areas.
By the way, it seems to me that cigarette use is much, much higher in other parts of the world than in the USA. Anyone have first-hand knowledge of this?