For everyone who was in some way influenced by their children to quit. While it should not be your primary reason for quitting, undoing the example you have set by being a smoker, and, more important now, setting the example that you can actually quit is an important secondary benefit to your children and other significant people in your life.
Think about it, what example do you want to be setting for your loved ones? That you are a smoker who cannot stop thus strengthening their belief that quitting is impossible for them too, or that if a person has the education, strength and fortitude they too can overcome this deadly addiction. If you choose the latter, to continue setting the example that it is possible to stay smoke free, always remember to show yourself and others that you have the full ability to never take another puff!
Joel