The ultimate “soccer mom” of the moment, Sarah Palin, loomed almost life-size from the cover of Saturday’s Good Weekend. But buried on page 79 of the giveaway magazine, in among the recipes and spring homemaker tips (“How to have a garden party”), was a full-page advertorial for Coca-Cola featuring perhaps an even more surprising choice of front person than the Republicans Party’s.

Actor Kerry Armstrong stared out of the page smiling, sitting cross-legged by a pool and framed in the unmistakeable shape of a Coke bottle. The rather copy-dense page (so you knew it was serious) was headlined, in Coca-Cola red, “Kerry Armstrong on Motherhood and Myth-busting”.

There was a brief “personal” message from Kerry, whose more “maternal” roles of late have included an unfortunate widow in Bed of Roses, a pushy stage mother in Razzle Dazzle and of course Heather Jelly in Sea Change. She explained that:

As a mum, I am often bombarded with conflicting messages about food and drinks… When I was asked to speak out in favour of one of the world’s largest brands, “Coca-Cola”, it became clear that it was surrounded by all kinds of myths and conjecture…

Armstrong’s picture is surrounded by a series of paragraphs, each of which is headed by a “Myth” about Coca-Cola and explanatory text “busting” the myth. You know the kind of thing: Coke rots your teeth, Coke is loaded with caffeine, Coke makes you fat, Coke originally contained cocaine, etc.

Armstrong certainly looked sincere and I guess she may be an aspirational or inspirational figure for mums of a certain age. But she’s an odd choice as a spokesperson or endorser for Coke, when they seem to be striving for credibility.

While she is well-known for supporting a variety of causes, my impression is that, while well-liked, many people regard her as a little bit loopy. Check out this interview she did with George Negus a few years ago and see if you are any the wiser about the “seven Kerry Armstrongs” by the end.

And if you visit the Coca-Cola website you’ll find — perhaps not surprisingly -– that the “myths” part isn’t actually the result of Kerry having been allowed to wander around the Coca-Cola organisation and conduct her own investigation: it’s pure spin.

The same “myths” are related essentially word-for-word on the website but with no mention of Kerry Armstrong. There’s also a related TV commercial in which a voice-over — is it Michael Caton? — explodes the same myths. (Sadly, the more exciting myths about the contraceptive capacity of Coke or its hallucinogenic properties when mixed with aspirin don’t get a run.)

In other words, Kerry Armstrong is truly just a front person for the campaign. And it’s a surprising choice of product endorsement for an actor who has previously supported a variety of worthy causes with a lot less money and marketing clout than Coca-Cola.

Intriguing, too, that she told the Herald Sun earlier this year that “I have had to turn things down that could have brought me great financial freedom because I knew the audience would not appreciate them”. Apparently not this time.

But this whole Coke campaign is pretty strange all round. Like McDonald’s “facts” campaign a few years ago and KFC’s current efforts, you wonder whether it wouldn’t be a better strategy just to ignore the scuttlebutt and not dignify it by responding.

People didn’t suddenly stop drinking Coke or eating KFC because of the ridiculous playground rumours circulating in my adolescence that Coke dissolves two-cent pieces (ah … so that’s where they all went) or that KFC was not actually “C” but some other animal starting with “R”.

And the sign-off line of Kerry Armstrong’s personal message — “My boys now call me Mum the Myth Buster” — has got to be one of the lamest of her career.

Dr Stephen Downes lectures in the postgraduate advertising program at RMIT University and is a market researcher with QBrand Consulting.