Opinion: Perspective - Boots shows why ad promise must match reality

You don't have to delve very far into the advertising process to understand quite how much advertisers worry about their advertising. But it's quite rare to find an advertiser who worries about their ads working too well. So there's a tangible irony in the news this week that Boots' advertising has simply been too damn effective.

Boots' recent ad campaign starring Jonny Wilkinson and inviting customers to pop in for a free cholesterol test has had a finger-wagging from Ofcom after the retailer was overwhelmed by the number of people wanting the test and failed to keep pace with demand.

Of course, you might think that super-effective advertising should happen more often than it does. After all, we live in an age when advertising is subjected to crippling amounts of pre-testing, endlessly focus-grouping the likely consumer reaction and all too often reducing great creative ideas down to the lowest common denominator ingredients.

After all this, it would be nice to think that the end result really shifted some product.

And in the current risk-averse climate, where every decision (particularly ones that involve hundreds of thousands of pounds of marketing budget) are agonised over and buck-passed on to researchers and consultants, the search for proven effectiveness can be as consuming and draining as the pre-testing. Clients search endlessly for proof that their advertising (in isolation from their price promotions, PR, competitor activity or any one of another hundred influences on sales performance) is working.

Such proof of effectiveness Boots now has in abundance. Of course, the success of the campaign has less to do with Mother's execution (fine though the work is) or the decision to use golden-boy (and ad tart in the making) Wilkinson, and more to do with the fact that the nation is increasingly worried about such things as cholesterol levels ... and we bargain-obsessed Brits love something-for-nothing.

Either way, the campaign worked too well and Ofcom has now decided that the ad (later amended by Mother to stipulate that the offer was for people over 45) was in breach of the rule on qualifications in the Advertising Standards Code and was misleading. Quicker than you can say "remember Hoover", advertising effectiveness has become a problem for Boots, and the retailer was this week mulling over the implications of quite how well its advertising has worked.

There is a double irony at play here. Boots is a brand desperately in need of a stronger positioning and a clearer brand strategy. The store itself is under siege from the supermarkets (who isn't) and its "lower prices you'll love" strategy has been blamed for a drop in margins. The cholesterol-testing notion was a smart idea for driving store traffic, underlining a "caring" image and - in the absence of a big branding idea - kept the store's name front of mind. Before this, Boots' highest-profile advertising had been for its range of sunscreens, not exactly a great hook on which to hang your main TV advertising presence in a summer where sunshine was rather too infrequent (in one week in August, Boots actually sold more cold and flu products than sun creams).

Now some of the customers motivated by the Wilkinson ad have been frustrated by their in-store experience, to the extent that the success of the campaign has actually had some negative impact on perceptions of the Boots brand.

This is one painful advertising example of when getting it right really means getting it wrong.