The number of people who have tried e-cigarettes has risen from 9% in 2010 to 35% in 2013, as smokers look to kick the habit.
There are 1.3 million users of e-cigarettes in the UK, according to the latest estimate by public health charity Action on Smoking and Health (ASH).
Almost all of these people are current or ex-smokers, with as many as 400,000 people having replaced smoking with e-cigarette use, says ASH.
E-cigarettes deliver vaporised nicotine without the harmful toxins found in tobacco, and are seen to be a safer alternative to traditional smoking.
January best time to quit smoking
With new year’s resolutions still fresh in the mind, many smokers are using these "fake fags" to wean themselves off tobacco.
January is one of the best times to give up smoking, according to research from the University of Stirling, which says New Year’s resolutions can help you quit forever.
Linda Bauld is professor of public health at the University of Stirling in Scotland.
She says: "Studies show that one of the biggest factors in predicting if someone will stop smoking is how motivated they are.
"A January deadline can give a bit of extra motivation."
However, the research also showed only 4% of smokers who try to give up by relying purely on will power are likely to succeed.
'Why I turned to e-cigarettes'
This is leading to more and more people looking to tobacco alternatives, such as e-cigarettes, to help them quit.
One such smoker is Tim Warren, a 33-year-old customer service advisor from Liskeard in Cornwall.
He said: "I decided to take up smoking e-cigarettes in November for the obvious health benefits, and also because they save me money - up to £30 a month.
"Personally I think they've been great, because I already feel I have more energy when I exercise.
"I'm getting the nicotine that I need without the harmful side-effects.
"They really are just like smoking a real cigarette so for anyone looking to give up tobacco it is a great place to start."
E-cigarettes regulated as medicines from 2016
E-cigarettes are due to come under the control of the Medicines and Healthcare Products Regulatory Agency (MHRA).
This move is to quell any concerns about long-term health risks.
However, this law change, which will see electronic cigarettes become regulated as medicines, won’t come into force in the UK until 2016.
Can e-cigarettes cut your life insurance cost?
Matt Lloyd, head of life insurance at Confused.com, said: "It's interesting to see how the popularity for electronic cigarettes has surged over the last year.
"But as it stands, if you use e-cigarettes, you're still deemed as a smoker by all life insurance providers and therefore charged smokers' rates."
Lloyd added: "Currently, there’s a lack of objective evidence on the long-term effects of this product, which makes it difficult for insurers to assess the level of risk they pose.
"However, this may change when electronic cigarettes come under regulation by the MHRA."
Smokers pay more for life cover
But, Lloyd said, kicking the smoking habit is one of the most effective ways of driving down life insurance costs.
"To illustrate this, a 30-year-old non-smoker could get cover from as little as £5 a month, when insured for a 25-year policy that will pay out £100,000 in the event of death.
"But a 30-year-old smoker could find themselves paying £8 a month for the same cover. That’s 60% more and, over the 25-year term of the policy, adds up to an extra £900.
"So if you have abstained from smoking for 12 to 18 months, it's worth contacting your insurer to see if this will make any difference to your monthly payments," Lloyd said.