You don't have to be mad to use Twitter, but it helps...

On the courses I run for the Chartered Institute of Marketing and University of the Arts London, there's inevitably more and more discussion of so-called 'social' media such as networking and microblogging sites. Twitter has grown hugely in recent months thanks to high-profile endorsements by celebrities. These range from American A-listers like Demi Moore and Willie Nelson through to UK talkshow hosts Philip Schofield and Jonathan Ross.

But how exactly can Twitter and other similar sites actually benefit marketers and advertisers? A clue may lie in the work being done with AMC's Golden Globe winning TV show Mad Men. The series is set in Madison Avenue, New York in the early 1960s and features an array of glamorous but rather unsympathetic characters who populate an ad agency called Sterling Cooper. Viewers in the UK can currently catch the second season on BBC4 and BBC2.

Actors from the show such as Jon Hamm use the site in a pretty typical way, posting about everything and nothing in 140-word bites. What's far more interesting, however, is the way that the characters from the show interact in real time on Twitter. Neurotic housewife and former model Betty Draper, for instance, tells of the meals she's preparing for her husband Don. Recently she posted that the creative director had taken a trip to Austin, Texas and remarked on how far afield businessmen seem to get these days. These days, of course, being 1962 rather than 2009.

When I responded to the tweets of one of the other characters - copywriter Peggy Olson - and told her that she shouldn't forget her roots, she was sweet enough to reply. She'd never forget she came from Brooklyn, she told me, but her career in Madison Avenue was where the future lay.

At one level, this is all completely bizarre. I am a real person in 2009 communicating with a ghostwriter for a fictional character who lives in the era of JFK. Some people might tell me to get a life and perhaps they're right. I can't help feeling, however, that this ability to interact with the characters cements the relationship that the viewers have with the show. And what do the TV producers know? Stronger relationships mean greater loyalty, more viral referrals and higher viewing figures. And higher viewing figures mean greater advertising revenues.

Perhaps when the history of 21st century marketing communications is written, the book won't start at the Millennium. It will reach back to the days when smoking was a mark of masculinity, Vermouth flowed freely during office meetings and the Mad Men ruled the roost in Manhattan.

© Phil Woodford, 2009. All rights reserved.

Phil Woodford is a freelance trainer and creative who lectures in marketing and advertising at Birkbeck College, University of London.