I recently sat and watched a debate on new advertising models. On the panel were the heads of a big UK advertising agency and one of the few surviving new media agencies. Someone pointed out to them during the coffee break that they shared a particularly big, high-profile telecoms client. There was something really odd about the way they dealt with this encounter. It wasn't the fact that they were obviously unaware of each other's role in their shared client's business. It was the total lack of interest in what the other did for their client that was truly bizarre.

Poor relationships between creative agencies serving the same client are nothing new. Mutual indifference between old and new media isn't new either. In this instance, however, the lack of interest from the advertising agency could be suicidal. The client in question is about to embark on a programme of interactive TV advertising, and the advertising agency hasn't even been considered for the work.

Interactive TV is where the divisions between old and new media start to get a bit confused. You would have thought that advertising agencies would have fought tooth and nail to control how their clients' brands are presented on TV. However, most advertising agencies seem to have dismissed interactivity as the last gasp of the internet marketing bubble. The irony is that interactive TV desperately needs the combined minds of the advertising industry to drive its development as a creative medium.

Interactive TV is something they should be good at. TV has always been the advertising agencies' default weapon, but it is not the only thing they can do. It seems strange that advertising agencies are able to claim authority in media as diverse as linear TV, posters and print, while ignoring something so TV-centric as interactive TV.

Agencies have been cosseted by the fact that, for most clients, interactive TV advertising is not yet appropriate and can't deliver against commercial objectives. But its time will come. There is a growing belief that simple, 30-second TV ads will become just one of many options available to clients looking to use TV, leaving advertising agencies increasingly marginalized.

Advertising agencies have been losing influence in their client companies for a decade. Now, as the palette of creative options expands, they risk getting pigeon-holed as implementers of just one type of solution. New media agencies, who view TV interactivity as a trojan horse to becoming "proper" advertising agencies, lack experience in traditional media. Hopefully, in the next wave of agency mergers and start-ups, a new hybrid breed of creatives will emerge who can embrace the "new" while still understanding and exploiting the "old".

nigel.walley@decipher.co.uk

Nigel Walley is managing director of digital strategy consultancy Decipher