If we can get a 25% reduction in minors initiating nicotine use then there is a good chance they will never smoke. From a Surgeon General's report (last sentence is the most important):

 Among adults who had ever smoked cigarettes daily, the mean age (in years) of smoking initiation was 15.3, and the mean age of beginning to smoke daily was 18.2. Among adults who had ever smoked cigarettes daily, 86.9% had tried their first cigarette by the time they were 18 years of age, while an additional 11.5% did so by 26 years of age. About two-thirds (64.3%) of adults who had ever smoked daily began to do so by 18 years of age, and almost one-third of adults who had ever smoked (22.7%) began to smoke daily between 18–26 years of age. Virtually no initiation of cigarette smoking (<1.5%) and few transitions to daily smoking (<4.3%) actually occurred in adulthood—that is, after 26 years of age.