What makes TV addictive?

Millions are turning on to see Big Brother, just as they did to watch Who Wants to be a Millionaire? But what makes television addictive? By BBC News Online's Giles Wilson.

The satirical television listings website, TV Go Home, might be on to something.

In its current issue, it includes a fictitious programme called Text Message Theatre. "A cast of actors clutching mobile phones read lines and enact stage directions being sent in by viewers at home," the entry reads.

By each cast member's name in the programme listing is a mobile phone number for the audience to send in its suggestions.

This is all very amusing, taking the current trend for docusoaps and interactive programme formats to its logical - if ridiculous - conclusion.

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But who could say with certainty that by next summer, Text Message Theatre will not be topping the ratings and getting coverage in all the serious and tabloid papers?

The idea may tempt TV executives looking to capture the public's imagination, as they have done this year with Channel 4's Big Brother.

The hugely successful "fly on the wall" show has hooked an audience of more than three million - Channel 4's highest in a long time. But what is it that makes television so addictive?

Why does Who Wants to be a Millionaire? steamroller through the TV schedules, flattening any other programme in its path?

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And why, week in, week out, do Coronation Street, EastEnders, Neighbours, Emmerdale and Brookside demand hours of attention from their followers?

The effect Big Brother and its website have had on viewers has been so dramatic it led to this editorial in, of all places, The Daily Telegraph: "[T]he programme will become unmissable. Are we being prurient? Yes. Salacious? Undoubtedly. But, for sheer entertainment, this is hard to beat."

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Big Brother's alter ego, the boss of production company Bazal, Peter Bazalgette, knows if the job is done right, it's a sure-fire winner.

"If you get in touch with the characters, it's compulsive," he said. But if you don't, "it could be like watching paint dry".

TV audience analyst Mallory Wober says the Big Brother audience would be a large number of "visitors" who might watch two or three times a week.

Office gossip

"Hardly anybody will watch it five times a week. But people will come in and see it, in order that they can talk about it with their friends who have also seen it. And they do that because it's stoked up by the press. The press relies on television and to some extent television relies on the press."

Wanting to keep up with the conversation in the office, and feeling a group involvement in what's going on certainly gives some incentive to watch. As does the daily reinforcement of the characters and the slowly brewing events.

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"And there is the interest in human relationships - especially if the people are real, or semi-real. And what's wrong with that?" says Mr Wober.

Like Who Wants to be a Millionaire?, Big Brother shares vital aspects with the soaps: some insight into human behaviour, and lots of cliffhangers. Unlike the soaps, though, these programmes have interactivity as a bonus.

Dick Fiddy, television consultant for the British Film Institute, says the attraction of Big Brother is little more than voyeurism. But he adds: "The format obviously holds water, because it works all over the world. It's like having a knot-hole through the neighbour's fence.

Getting a fix

"There's also the unpredictability - the element of being able to vote someone out each week and some of the other characteristics of the programme certainly add to the number of cliffhangers.

Many people might feel a compulsion to turn on the television at the time of their regular soap. But Mr Wober rejects any notion television can actually be addictive.

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"When you go on holiday, do you notice what you've missed? Do you show any withdrawal symptoms, by which I mean anything physiological? Do people in Ibiza have headaches, sweats and bad dreams which are attributable to separation from Coronation Street rather than whatever else they are doing in Ibiza?"

And while Channel 4 rubs its hands, Mr Fiddy is not sure Big Brother's appeal will last. This series and perhaps a second, but that is about it.

"I don't think it's going to survive for too long. It has got fad written all over it," he says.

And so television bosses will be frantically looking for the next fad. Which is where Text Message Theatre could come in.