Media: The bottom line is: does it sell?: The slick ads are sexy and witty, but the client also wants them to work. Tonight will decide which do that best, says Meg Carter

Does advertising work? Sceptics will find out at the Advertising Effectiveness Awards in London tonight, where shortlisted campaigns as diverse as Wonderbra, British Airways and Pepperami will vie for the prestigious Grand Prix.

As the worst effects of the recession fade to memory, many in the media are now breathing a sigh of relief that they have turned the corner. Companies spent around pounds 9bn on advertising last year and this figure looks set to rise after declining steadily since the late Eighties, according to the Advertising Association. But it's not quite business as usual.

For today the buzz word is accountability. Increasingly advertisers are asking, 'Is this money well spent?', and they want proof. 'There is a huge emphasis on generating immediate sales, tomorrow,' says Beth Barry, joint planning director at Ogilvy & Mather.

This has affected the role played by traditional media, such as TV, the press and posters, whose market share is falling - from 45 per cent of total UK promotional budgets in 1988 to 40 per cent in 1993. And a similar pattern has emerged in the US. The reason for this is that companies such as Heinz are turning to direct mail and sales promotions - activities which are far easier to measure.

Gauging the effectiveness of an advertising campaign is a notoriously imprecise science. It takes more than simply adding up the number of packs sold. The impact of the advertising must be assessed in total isolation from other factors, such as product innovation and editorial coverage.

'A lot depends on what the advertising is trying to achieve,' says Paul Edwards, planning director at the SP Lintas ad agency. While some campaigns are designed to get people to buy a product, others are created to maintain rather than develop a brand's market position. 'Sale increases are not necessarily a relevant measure,' Mr Edwards adds.

The Institute of Practitioners in Advertising's effectiveness awards are the only scheme to judge ads on anything other than subjective, creative criteria. Sales data, qualitative research and circumstantial evidence for each campaign is gathered and carefully assessed. As a result, most industry veterans praise the objectivity and accuracy of the judging process.

'Advertising isn't easy to evaluate because it works in many different ways and on many different time scales,' says Chris Baker, convener for the IPA awards and planning director at the ad agency Bainsfair Sharkey Trott.

'Smart marketing is about orchestrating all elements in one direction.' The candidates on the IPA shortlist prove the point.

After the launch of the 'Hello Boys' Wonderbra poster campaign, created by the ad agency TBWA, weekly sales soared by 7,000 - almost double the figure for the same period last year. The ads feature the blonde model Eva Herzigova in her underwear alongside saucy captions, including '. . . Or are you just pleased to see me?'. They have been singled out for generating an immense amount of publicity despite costing only pounds 330,000, a relatively modest ad spend.

Sales of Boddingtons bitter have trebled since the 'Cream of Manchester' campaign was launched in July 1991 by Bartle Bogle Hegarty. While rival beer advertising traditionally uses television and relies on laddish stereotypes, Boddingtons emphasises its creamy head using simple but stylish visual puns on the 'Cream of Manchester' theme. The campaign is praised for helping to turn Boddingtons into a national brand without losing touch with its regional roots.

Sales also rose significantly for the meaty snack Pepperami after SP Lintas unveiled its 'Bit of an animal' TV and cinema campaign, which featured an animated sausage stick. Sales increased by 33 per cent in the six months after the campaign broke - equating to an extra 95 tonnes of Pepperami.

Also shortlisted are the long-running campaigns for BMW and British Airways.

Both have developed their brands successfully over a long period, boosting both image and sales, the judges found. BMW has used the 'Ultimate driving machine' theme since it began working with its current ad agency, WCRS, in 1979. Since then sales have trebled.

Mr Baker at Bainsfair Sharkey Trott says the IPA awards are more relevant today than ever. 'In more challenging economic conditions there is a need to justify the value of advertising,' he says. He believes that judging purely on creative merit misrepresents the business: 'It is a commercial tool, after all - not part of the arts.' Even so, the winners of previous awards have demonstrated that innovation and creativity are important.

Even in 1992, the winners confounded accepted wisdom that advertising should play safe because of the recession. 'They were a good representation of the best and most creative advertising that year,' Mr Baker says. And so are the 1994 candidates. 'Smart advertisers realise that the real value of creative advertising lies not in its cost but in its added value, the ability to generate greater effect for less money - to be talked about.'

So what does make an effective ad? Better targeting and a closer understanding of the consumer is one factor, according to Mr Edwards at SP Lintas. 'There are now more clever ways to hit the right people at the right time and in the right mood,' he says. In the past week, The Body Shop has appointed its first ad agency, Chiat-Day, to develop ads using interactive media, and Land Rover has run three-and- a-half minute 'infomercials' in the centrebreak of News at Ten.

But there is not - and never will be - a magic formula, according to Ms Barry at Ogilvy & Mather. 'If we could identify what makes effective advertising, we'd all be doing it and we'd all be millionaires,' she says.

'Good advertising, such as for Hamlet, the Economist and Guinness, is usually effective.'

A campaign that 'works' is generally accepted to be one that encourages people to identify with, relate to and connect with the ad. To maintain this connection, it is therefore important for advertising to keep up with the audience's changing hopes and aspirations.

But this also means that what makes an effective ad is always in a state of flux. No sooner will an agency hit on the right approach for a particular audience at a particular time than a rival will do something different and rewrite the rules. Truly effective advertising, it seems, will always be the industry's Holy Grail.

(Photographs omitted)