One outlet selling them like hot cakes is the House of Fun.
Owner Patrick Shepherd said the Government's intention to define the law will definitely encourage people to leave tobacco behind.
"It think it's good news, it's really positive. If patches and gum nicotine replacements are legal then it makes sense this stuff is, too.
''Okay, so it is still nicotine and that's addictive, but I've been amazed at how easily some people who've been hardened smokers for years have cruised their way through giving up with e-cigarettes.
"When you stop smoking the nicotine is out of your body in three days, but it's your mind that can't give it up. It helps people cut down," Mr Shepherd said.
The devices and the nicotine liquid used in them will be a lucrative replacement tobacco for sales lost by retailers as more people switch to e-cigarettes, although Mr Shepherd said that shift has already been massive.
"New Year's Day was our biggest sales day ever for e-cigarettes," he said.
"We opened up specially because we knew there'd be so many people who made New Year's resolutions to give up smoking."
Emily Dixon uses both methods, but started on the vapour method several months ago to help cut down the number of rollies she smokes.
"It works and they are satisfying. They prevent me from coughing or feeling other effects from smoking too many rollies, and I can get the rum flavoured liquid to match the taste of my baccy."
While Ms Dixon agrees the same tobacco-free zones and sales laws should apply to e-cigarettes, she is more comfortable vaping than smoking tobacco when she's out because people near her do not get cloaked in or inhale smoke.
The vaporised nicotine is drawn into the mouth and throat rather than the smoker's lungs filling with tobacco smoke and its alleged 400 toxins.
Bridget Rowse, Northland Smokefree adviser, said she is pleased there is another tool to support smokers to quit, as long as they are properly regulated.
''This means that sales are restricted to pharmacies and a limited number of licensed specialist shops, with stipulations about proximity to schools, exclusion of minors from shops, training for staff in e-cigarettes use and stop-smoking support, and minimum age of purchase 18 years.''