Actually, when I ask for evidence I'm usually not asking the company or marketer directly, I'm asking one of several regulatory authorities (such as the Advertising Standards Authority (ASA) Trading Standards or the Medicines and Healthcare products Regulatory Agency) to investigate on my behalf.
In fact my strategy has generally been to research the claims myself and put forward a fairly detailed explanation of why I think something's not quite right. I don't put in a huge number of complaints but I have a fairly high 'success' rate (in that the material is amended, or an adjudication is upheld) though occasionally my complaint doesn't get taken forward.
Another thing I typically do is blog about the topic I'm complaining about, or the company itself. This means that people searching for information about it / them might find a blog post that is critical of the intervention and explains why the claims are misleading. This changes the Google landscape a tiny bit and an explanation of the reasons why a claim is misleading might put someone off wasting money on a treatment.
Complaining about misleading adverts
Whenever the ASA gets a complaint it contacts the marketer and asks for evidence or, if the claims clearly breach the advertising code it'll ask them to amend the ad. Either the organisation has evidence or it hasn't but in any case the outcome will end up on the ASA's website.
The basic publication is on a list of 'informally resolved' cases where the organisation amends the claims and no further action is taken. In more complex cases it goes to adjudication and is either upheld or not upheld (a good outcome for the organisation). In more extreme cases where the marketer refuses to amend claims they will end up on the ASA's non-compliant online advertisers list - this can lead to further problems including being passed on to Trading Standards (who can instigate criminal proceedings and shut organisations down) and having their site downgraded in Google search results).
Sense About Science have a series of guides to help people ask for evidence effectively, depending on who they're asking and what it is they need to ask for.
The guide covers asking
- companies about their product claims,
- politicians about things they've said
- and how to respond to articles in newspapers and magazines.
There are also examples given where people have asked for evidence, and whether or not they're still waiting for it or the advert has been withdrawn (I'm not sure if there are any where evidence has actually been forthcoming but that would be nice).
I've always thought that it would seem to be a kindness to give a company an opportunity to avoid a citation on the ASA's website by seeing if it's possible to resolve the misleading claims before snitching on them.
However I'm yet to find the right way to do this - and wondered if anyone had any ideas or if we've all agreed to just get on and report it. I wonder if people who are (let's charitably assume they're doing it unwittingly) making misleading claims would rather skeptics 'had a quiet word' before bringing things to the ASA's attention.
I've tried face to face, telephone conversations and emails but unfortunately there doesn't seem to be a way of communicating to someone that their advert is misleading without getting their hackles up. Or if there is I've not managed it (and I'm always Britishly polite about it even if they aren't).
Worse, I feel that I do have to tell them that if they don't change the advert I'm going to report it to the ASA and that just sounds threatening. So, much as I'd like to, I'm afraid I don't bother with the preliminaries and just report the misleading claims.