I'm addicted to nicotine, but my pipes are also a hobby. That's what differentiates pipe smoking from cigarette smoking, in my opinion -- one can plausibly be a hobby, but I have a hard time envisioning a cigarette hobbyist.
Thanks for this thread, BTW -- after some of the discussions on other threads recently, I had kind of wondered what a survey like this might reveal. I'd also love to see an age breakdown, as well, as my pet theory is that younger pipe smokers are more likely to consider themselves hobbyists while older smokers are more likely to call themselves addicts.