Not all smokers can successfully make the transition to vaping, new research shows.
The study, from the University of Otago, involved interviewing 20 "vapers" who also regularly smoked cigarettes, and has been published in international journal Tobacco Control.
It largely comes down to nostalgia and a strong attachment to "real" cigarettes, lead author Dr Lindsay Robertson says.
"Many started their quit attempt expecting that vaping would offer them exactly the same experience as smoking," she said.
"However, they often became disappointed when their experiences didn't replicate smoking, and continued smoking as well as vaping."
One way of addressing this problem could involve managing smokers' expectations more carefully, Prof Robertson says.
This includes ensuring smokers, who want to switch to vaping, receive good advice from well-trained retailers with specialist vaping knowledge.
"Participants see specialist vape-shop staff as expert advisers ... (so they) could help remind people of the importance of giving up entirely," says Professor Janet Hoek, who leads the Health Research Council-funded research project.
This advice could be very important because some participants thought they had been successful just by reducing the number of cigarettes they smoked rather than trying to give them up completely, she said.
The researchers said government legislation could help people make a full transition away from smoking to exclusive use of e-cigarettes and vape devices.
Hapai Te Hauora (Maori Public Health) chief executive Lance Norman says recognising the tough move away from smoking cigarettes was important.
"These [University of Otago] findings suggest we need to support our whanau in this transition with realistic expectations, and informed, well- trained health professionals," he said.