Big Brother is a cornerstone of Channel 4 output
TV schedulers are unlikely to see viewers switching off from reality TV just yet, argues BBC News Online's Darren Waters.
When reality TV first burst on to television screens critics were quick to label it a flash in the pan phenomenon, like docusoaps and the media career of Driving School "star" Maureen Rees.
But a fourth Big Brother series, a second I'm A Celebrity series and even a recommission for Fame Academy, once dubbed Lame Academy, are proof of the enduring appeal of the genre.
Not everyone is a fan - Culture Secretary Tessa Jowell recently said she hoped there would be a "viewers' revolt" against reality TV.
But viewers are not Labour backbench MPs, who revolt loudly and often.
I'm A Celebrity has attracted audiences of up to 10 million viewers, driving a steamroller over the opposition on other channels.
Drama, lifestyle and documentary programmes have all been crushed by the alluring mix of multi-camera, multi-star TV.
Fame Academy will return
BBC One's Servants, part of the established period drama genre, took a hammering in the ratings to such an extent that the prospect of a second series remains uncertain.
In contrast, a third series of I'm A Celebrity is a racing certainty.
In fairness to Ms Jowell, she did describe Big Brother as "compelling" but added: "You can have too much of a good thing."
She said: "My point is that reality television is not a moral ill, but it's a genre that should not be flogged to death."
Reality TV has secured career success for TV executives if not the shows' contestants
Producers have tried to keep their formulas fresh, and viewing figures have apparently rewarded their efforts: celebrity versions, bars in the Big Brother house, ever-more elaborate tasks, pop stars, pop idols, pop rivals.
Who would have thought that celebrities, even of the minor variety, would consent to appearing on TV 24 hours a day without a single dab of make-up and cut off from their agents and publicists?
The format has changed so much it is hard now to even define reality TV.
350 people worked on I'm A Celebrity...
The show cost £10m to make
ITV charged £100,000 for 30-second ads
Nearly a fifth of 16-34 year olds watched it
12.3 million watched Monday's finale
But 16 million watched the "Millionaire major" documentary last month
But after evolution comes consolidation and the fourth series of Big Brother will return to the original roots of the series.
Reality TV, it could be argued, has now established itself as a mainstream format, alongside drama and sitcoms, and if anything, is going through a mature phase.
Perhaps the enduring appeal of reality TV, whether in celebrity or "ordinary people" guise, has nothing to do with our appetite for the formula but more to do with gossip columns and the need for showbiz news.
The instant fix of celebrity gossip has become a mainstay of newspaper and magazine content in recent years.
Magazines such as Heat and Now, and showbiz columns such as 3am Girls, Bitches and The Goss, need a constant supply of "celebrity figures" and reality TV keeps the production line ticking over.
The traditional route to fame is slow and uncertain but reality TV makes instant stars of ordinary people and rejuvenates the former famous.
Little wonder then that the tabloid media is so conspicuously absent of criticism for the genre.
Reality TV will probably last as long as we crave our hit of celebrity gossip.
Certainly, there is little sign of commissioning editors turning their backs on reality TV quite yet.
Showbiz columns are hungry for content
Perhaps the test of the popularity of reality TV will be the fourth series of Big Brother.
Many felt the third run of the Channel 4 programme would flop but ratings confounded expectations.
And for the forthcoming series Channel 4 received a record number of applications, with more 10,000 people sending in home videos.
There seems little sign yet of any revolt.