As the fifth Big Brother series on Channel 4 comes to an end, BBC News Online looks at whether the format has passed its sell-by date.
Channel 4's Big Brother was recently voted one of the most innovative programme genres of all time, by a panel of TV experts for Radio Times.
The full line-up of Big Brother 5 contestants
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But innovation can quickly become dated if it does not continue to evolve and push boundaries.
After a moribund series in 2003, Channel 4 has been under pressure to restore interest in the format.
Their success can be determined in three ways - ratings, the numbers of eviction votes and tabloid press interest - and on all three counts the latest series has been a success.
The fifth series has averaged 4.9 million viewers, up 9% on the same period last year, although the peaks are not as high as in previous years - pointing to a series which has developed a core audience but is no longer able to generate the excitement of "event television".
Channel 4 long ago dropped any pretence that the show was a psychological experiment and has concentrated on making the programme the epitome of tabloid TV.
"It's all pantomime," Davina McCall whispers into the ear of each evicted housemate as they face the inevitable boos and cheers.
And as televised pantomime, Big Brother is the best thing on screens during the summer.
Amiable
Last year the series flopped because the producers chose a group of contestants who were so determined to be amiable and agreeable that it came as no surprise that the winner was a Bible-reading, Scottish virgin.
The warring parties had to be held apart during a mass brawl
The producers have made no such mistake this time, billing the series as 'Big Brother gets evil' and selecting 12 individuals seemingly on their ability to irritate and wind each other up.
The result has been explosive - literally. One late night row was so aggressive that security guards had to rush in to the house and separate the contestants, while distressed viewers called the police because they were worried about the scenes unfolding on their screens.
The fact there was anyone watching the programme in the small hours shows just how addictive this series has been.
The fighting factions, bickering, sexual tension and jealousy have made this year's series the most unmissable yet, driven by the TV producers' ability to divide the housemates and cultivate suspicion.
Nudity
Nadia is favourite to win the series
This series has also been marked by a degree of nudity not seen before - inhibitions were quickly shed in the house and the programme has been awash with breasts and bums.
Whether this has been a deliberate calculation by the producers or the general erosion of inhibitions over a number of series is not clear - but it has certainly ensured high profile coverage in the mass market papers.
And while the Big Brother sex barrier has also been broken this series, allegedly - it has been of secondary interest to the arguments and divisions that have arisen in the house.
The producers have significantly improved the tasks given to the housemates too - making the group chain each other up in pairs for several days was a master stroke, ratcheting up the pressure.
Big Brother ultimately stands or falls on the quality of its contestants - and in Victor Ebuwa, Nadia Almada, Michelle Bass and Marco Sabba, Channel 4 has unearthed some of the best pantomime characters in many years.
BBC News