The first thing any brand manager for a youth market product should do is telephone Mr John Reynolds, who owns the PoD Nightclub in Dublin, and say: "I'm fat and I'm 40 but I need to get by your doorman and into your club." It's not exactly textbook advice but, according to Mr Paul Keogh of DogHouse Management who spoke at this week's Marketing Institute's youth marketing evening, the key problem with brand managers is that they simply do not know what young people do or think and have never even had a one-to-one dialogue with them.

He added that the real target market of brand managers was senior management. This means over-reliance on research and Powerpoint presentations that begin with "research says", he says.

While Mr Keogh was with Guinness, he was part of the Budweiser launch and he later signed up Boyzone when he was managing director of Polygram. Now he runs his own consultancy, Doghouse Management. "Fifteen years ago, the research showed Budweiser simply wouldn't work in Ireland. It was the same with Boyzone, because qualitative on-paper research showed that an Irish version of Take That was a complete non-starter," he says.

"You have to delve deeper into what the research says and use it to solve problems." Youth marketing is a buzz phrase in PR and marketing, with several consultancies setting up specialist youth divisions. But, according to Mr Keogh, it's a convenient media term and it should be avoided by marketing professionals. It is usually taken to mean young people aged 12 to 25 years but there is a vast difference between the two extremes of this age group.

As someone who has focused on the youth market for most of his working life, mainly through the music industry, he left bewildered brand managers with one reassuring thought. "The youth market is the most difficult to understand because they don't understand themselves."