I can honestly say they never impacted my decision to smoke. I really loved smoking. The only thing that ever had any impact on me was the birth of my child and knowing that I wanted to live to see him grow up - and that he was counting on me.
Quitting smoking was absolutely one of the hardest things I've ever had to do - and my heart goes out to anyone that really wants to but can't. It's not the chemical addiction that makes it difficult as much as it is the physical habit. When I quit, I simply stopped seeing my friends that I used to hang around with out at the smoker's area at work. I became a more productive employee because my day didn't revolve around breaking to smoke a cigarette. In short, my whole world had to change. I associated smoking with getting up in the morning, driving, after meals, relaxing out on my deck in the evening and any time I had an adult beverage.
To be honest, the cravings still haven't gone away, only the frequency has diminished - and it's been two years. I see that cigarettes are now almost $5/pack in my area, but I don't believe the costs would be a deterrent. So, to sum it up, no, silly ads and billboards do absolutely nothing. You have to really WANT to quit in order to be successful. Anything less than a total commitment to cessation on the part of the smoker is going to result in failure.