Well, the total populations of New Zealand and Finland are 4.3 million and 5.3 million respectively. That is approximately one half of the New York City metropolitan area (the 5 boroughs and northern NJ). I don't know a lot about NZ but Finland has a much bigger problem than tobacco; we know it as vodka. Finland has one of the highest incidences of alcoholism in the world. Tobacco is an easy mark for those countries and I'm sure that the taxes collected on tobacco pale in comparison to those on booze.
The efforts here will certainly intensify but history has shown that prohibition of any type has always failed.