By Ian Youngs BBC News Online

I'm a Celebrity... Get Me Out of Here! was conceived as TV's holy grail.

The idea was that eight minor celebrities were stranded in the jungle with viewers given the power to be really rather nasty to them at the touch of a button.

The sadistic appeal of being able to be cruel to stars who are more often seen in the pages of Hello! was coupled with the addictive Big Brother-style formula of fly-on-the-wall "action".

Average eviction viewing figures

Geller: 7.5m Benn: 7.5m Day: 8.3m Cameron: 7.6m McAndrew: 7.3m Hamilton: 7.7m

The show has undoubtedly become one of the television events of the summer, a talking point that has generated countless column inches and water cooler conversations.

But steadily improving viewing figures have not given way to a ratings phenomenon.

About 7.5 million viewers watched the first two eviction shows, in which it was revealed that viewers had voted to kick out psychic Uri Geller and ex-boxer Nigel Benn.

Nearest equivalent

That was about the same as other prime-time week-night shows like Airline attract - but fewer than soaps like Emmerdale and Coronation Street.

It was significantly less than its nearest equivalent, Celebrity Big Brother, which saw six similarly minor stars imprisoned in a reality TV house for a week in March 2001.

About 10 million tuned in to see another ex-boxer, Chris Eubank, become the first to be evicted from that show.

The group was supposedly stranded in Australia

Singer Darren Day's departure proved to be a crowd-pleaser on Celebrity Survivor with an average viewing figure of 8.3 million and a good share of the total audience on Wednesday.

Fewer viewers tuned in for comedian Rhona Cameron's departure the next day and by Friday the average audience had dropped to 7.3 million for demure model Nell McAndrew's exit.

However the show comfortably beat the competition from the BBC on Tuesday, Wednesday, Thursday, and Saturday.

And importantly, viewing figures for the show have steadily increased during the hour it is on.

'Mindless rubbish'

The hundreds of viewers who have e-mailed BBC News Online with their views are roughly split - half love it, while the other half think it is a new low for UK television.

"The British public's appetite for watching mindless rubbish utterly amazes me," wrote one reader, Craig H.

"Without doubt the finest entertainment programme ever made," a viewer, Tom James, said.

The contestants were given harrowing "bush tucker trials"

Another, Lorna, wrote: "I must say I find this quite entertaining. I do find some of the celebs childish and irritating - but, hey that's the fun of it."

Many expected I'm a Celebrity... to be more compelling than Celebrity Big Brother as the public could vote to subject the stars to harrowing daily tasks, rather than just watching them sit in a house.

In the first week, viewers voted for who they wanted to be subjected to the daily "bush tucker trial" - the task that could earn the whole group a hearty meal if completed successfully.

It was no surprise that socialite Tara Palmer-Tomkinson was voted for to do the first one, which involved standing under eight buckets of creepy-crawlies and other assorted jungle mush.

ITV have finally broken right through the bottom of the barrel

Dave Johnston

Viewers apparently wanted to get her back for her easy ride through life. The tables were turned.

Other tasks have seen the vegetarian Geller eating live bugs and entertainer Darren Day dipping his hands into eight tanks of snakes, cockroaches and other assorted critters.

A seemingly endless round of rows and tantrums have also kept the drama levels high.

Cultural values

But the ratings, despite improvement, have remained solid rather than spectacular.

ITV director of programming David Liddiment recently criticised the BBC for doing a "terrible disservice" to British cultural values, being driven by ratings and "not a lot else".

But some viewers are complaining that ITV has gone too far downmarket.

"A group of people, stuck in one place, given tasks to do, and someone gets voted off periodically - it's been done to death," wrote viewer Paul Hawkins.

"ITV have finally broken right through the bottom of the barrel," wrote another, Dave Johnston.