I don't know, aren't they? It depends what you mean by pure, doesn't it? Is any vice-like a cream cake or a pint of amber nectar "pure"? Or does pure mean natural, lacking additives, organic even? Certainly this doesn't apply to e-cigarettes.
This has been part of a recent campaign for electronic cigarettes-"Just pure satisfaction for smokers." Not vapers, as smokers of e-cigs are called, but smokers.
The advert shows a female acrobat or any case gymnast, flying through the air pursued by an almost conical puff of smoke. Such images do an advertising agency, and no doubt Madison Avenue in the US in full of such pictures in the days of tobacco advertising. Although, it was banned, e-cigarette advertising is now creating controversy.
For some reason it worries people to say that e-cigs satisfy. What do they want, I wonder? A product that doesn't work? An e-ciggy you can't use? Something broken or ineffective? I'm not sure.
Or maybe it's all due to political correctness. You can't (in the UK anyway) use a tagline for e-ciggies which can also use for cigarettes. It gives off the wrong impression, at least this is what is popularly thought.
This isn't the first e-cigarette advert that has been complained about in the UK. In 2013 an e-cigarette advert received about a thousand complaints saying it was too sexual. This might seem surprising as it showed no sex scenes or even naked bodies but merely relied on innuendo about "putting it..." (that is, the e-cigarette) "...in the person's mouth." Not exactly pure, but not that offensive?
That campaign was notable by being the first e-cigarette commercial or television advert for the UK. This idea of Big Tobacco advertising its product, despite it being an e-cigarette, rather than a cigarette was never going to be popular. It is difficult to distinguish the outrage for the product with the outrage for its tagline, maybe? Who can tell?
There have been many famous cigarette advertising campaigns-"Happiness is a cigar called Hamlet" for instance. But TV tobacco advertising was banned as early as 1965, but was advertised in billboards and magazines until 2003, and shop adverts weren't banned until 2004. These are all UK dates, by the way.
It seems that American electronic cigarette adverts are even more obscure, with the tagline "No regrets." Another one has the tagline "Sociability reborn" which seems rather bizarre to me. Instead of TV they are looking at social media, like Facebook.
Also in the US it seems that advertisers are using the tactics their predecessors did with cigarettes with lines such as "a perfect puff every time." You puff cigarettes, but as I said above, you vape cigarette.
Another tag-"freedom to have a cigarette without the guilt" may seem to work, but now you're getting into the health complications of cigarettes versus electronic cigarettes.
I think the relevance of all this is that electronic cigarette advertising is a complicated area. There is a bit of a tightrope to walk here, really by the advertisers.