Pre-1990: For decades, the unwritten code of practice among advertisers - in public, at least - is to recognise the sanctity of the utter separation between editorial and advertising issues, especially where newspapers are concerned.
(Magazines are frequently bullied in more subtle ways.) When faced with bad reviews, advertisers refrain from threatening to "leverage" their ad budgets, however damaging they believe negative coverage to be.
The 90s: In a steady stream of television airtime disputes, advertisers and their agencies discover a new streak of ruthlessness in their tactical use of budgets. The ploy is to issue an ultimatum and if the media owner doesn't cave in, the advertiser pulls all of its budget out of the sales point.
Five television, the weakest of the mainstream terrestrial broadcasters, becomes a favourite target of this negotiating strategy.
April 2004: Several German companies consider a boycott of the Express group titles after its proprietor, Richard Desmond (pictured), allegedly goosesteps around the boardroom and then claims all Germans are Nazis. In the end, none takes action.
January 2005: But companies have no such qualms when cash is more clearly at stake - as MG Rover shows when it pulls all its advertising out of Express Newspapers after the group tries to impose rate increases of more than 7 per cent.
The car manufacturer points out that the group's circulation performance doesn't merit increases of this nature and declines further negotiation.
It later denies it has taken punitive action, but its ads don't reappear in the titles.
Now: Marks & Spencer is the first advertiser to put overt pressure on the editorial side of a paper when it pulls its ads from the Daily Mail, The Mail on Sunday and the Evening Standard in response to scathing coverage it has received in the business pages of all three titles.
Fast forward: 2006 - ISBA attempts to mediate as the situation rapidly deteriorates, with disputes arising on an almost weekly basis. It proposes a points system overseen by an ombudsman, with each abusive story about an advertiser automatically triggering fresh levels of advertising discount. But publishers resist another ISBA idea - officially accredited advertiser representatives sitting in on every editorial meeting.