I think at one time smoking in films influenced people to smoke, or at least made smoking seem to be the "hip" thing to do. These days, people are keenly aware of the health hazards of smoking, so most (emphasis on most) people are not going to be influenced by what they see on TV or the big screen.
Personally, I've lived this long without being influenced by what I see on the screen, I think I can live the rest of my life without succumbing.
