Opinion: On the Campaign Couch ... with JB.

Q: I am a digital marketing specialist who is sceptical that anybody really knows what 'the line' is anymore. Please explain. Above, below, on, off or through. What is it?

A: Once upon a time, O Best Beloved, there was an ingenious device called a commission. Let me explain it to you. I expect you think that advertising agents were called advertising agents because they acted as agents for their advertising clients? Wrong. Ad agencies traditionally acted as agents for media owners. When they sold space in a given publication to a client, the client would send a cheque to the agent; the agent would keep a bit for themselves ('the commission') and send the rest on to the publication.

If advertisers wanted to buy direct from the media they qualified for no commission so buying from an agent was no more expensive. Agencies were paid by the media: to the clients, they were free. And since those agents, still at no cost, not only provided a media schedule based on readership data but quite soon words and pictures as well, advertisers got an amazing deal. Thus it came about that the most valuable contribution an advertising agency could make to an advertiser - a brand idea of great persuasiveness and longevity - was never paid for. It came as free as a DVD in The Mail on Sunday's polybag. It still sticks in the craw of creative people but it's true: from the very beginning, their work was no more than an on-pack offer, designed to sugar-coat the cost of media.

However, other forms of sales promotion didn't work like this. Clients bought display cards and brochures and merchandising material direct from their producers - for an agreed fee. So when an ad manager clambered up on to his stool, adjusted his celluloid cuffs, dipped his pen in his inkwell and began to itemise his company's promotional expenditure for scrutiny by The Board, he would make a distinction. Commissionable items, media costs, would be listed first. He would then draw a line; and below that line, he'd itemise the lesser expenditures.

So you can see that 'the line' never really meant anything of significance.

It became significant only because cunning and duplicitous advertising agencies conspired to give it significance. Threatened by sales promotion techniques, whose effectiveness could be calculated more quickly and more accurately than that of an advertising campaign, they decided to portray all non-commissionable activity as grubby, socially inferior and ...