The number and type of e-cigarettes available online has soared within the past couple of years, with around 10 new brands and more than 240 new flavours coming to market every month during this period, reveals a study published in a special supplement of Tobacco Control.
The study is one of nine pieces of research on e-cigarettes to come out of the State and Community Tobacco Control Research (SCTC) Initiative, funded by the US National Cancer Institute at the National Institutes of Health, and published in the supplement.
The researchers base their findings on a comprehensive trawl of online English language websites marketing e-cigarettes between two specific periods - May to August 2012 and December 2013 to January 2014.
They looked particularly at brands (older and newer); models ('cigalikes', which resemble conventional cigarettes); eGos, which are larger and usually have a removable tank containing liquid nicotine; and mods, which are larger still and endlessly customisable), flavours; nicotine strengths; ingredients; and product claims.
The first search identified 288 unique brands, 37 of which had disappeared by the time of the second search, which identified a further 215 new brands.
By January 2014, there were 466 different brands, each with its own website, and 7764 unique flavours. Nearly all brands offered tobacco and menthol flavours. The next most popular category of flavour was fruit, followed by dessert/candy, alcohol/drinks, snacks/meals.
In the 17 months between the two searches, there was a net increase of 10.5 brands and 242 new flavours each month.
A comparison of the older and newer brands showed that older brands were more likely to push their 'cigalike' qualities (just under 90% of older brands compared with just over half of newer ones).
Older brands were also significantly more likely to claim that they were healthier and cheaper than conventional cigarettes; that they offered a good substitute in areas were smoking is banned; and that they were effective smoking cessation aids.
Newer brands were more likely to focus on choice and versatility. They offered more flavours per brand than their older makes (49 compared with 32), and they were less likely to emphasise 'cigalike' qualities.
Around one in 10 older and newer brands made direct claims about the effectiveness of e-cigarettes in helping smokers quit.
The US regulator, the Food and Drug Administration, has recently categorised e-cigarettes as a tobacco product, so sales to minors will be banned. But this ban does not cover the internet, where up to half of the total quantity of e-cigarettes sold are purchased, the authors point out.
Since the arrival of the tobacco industry into the market, money has been ploughed into advertising, helping to spur growth, but no large advertising budget is required to achieve a web presence, they add. In the USA alone, the e-cigarette market is projected to reach US$2 billion this year.
"The number of e-cigarette brands sold on the internet is large and the variety of flavours staggering," write the researchers.
They also note the shift in marketing tactics for these products, from conventional cigarette substitutes, only better, to styling themselves as new nicotine delivery systems, offering consumer choice in models and flavours.
As yet, it's unclear what impact this rapidly expanding market will have on smoking uptake and cessation, which poses "significant challenges to regulatory policy making," they conclude.