Ten years ago, a friend at work tried to quit smoking twice during the time that I knew him, and failed both times.
Recently, a friend bought electronic cigarettes. Someone warned that nicotine is addictive, and his response was: "I'll quit for three weeks. If I succeed, then it's not addictive." He successfully quit for three weeks. That same friend is now noticeably thinner, which he attributes to nicotine reducing his appetite.
I was talking to someone at a party. He claimed that he did not like to be in large groups of people, but with nicotine, he could manage it.
I was talking to another friend who I saw smoking an electronic cigarette, and asked about addiction. He claimed it was not addictive if you have something better to do. He cited the common example of some alleged experiment involving mice where the mice choose cocaine over food to their ultimate death. He claimed that if the mice had access to a nice environment, as opposed to being stuck in a cage with a cocaine lever and a food lever, then they would roam around in the nice environment over cocaine. I don't know if that's true, but his claim was that addiction has less to do with dependence on a drug for it's own sake, and more to do with a lack of something better to do.