Fans include Cherie Blair and Sir Paul McCartney, and you can get everything from a private jet to a bucket of water. Nick Morrison looks at how a nation of shopkeepers has embraced the ultimate global marketplace.

WHEN David Beckham's left leg went from under him, and his right leg skied the ball high into the stand, a nation's hopes tumbled as England went crashing out of Euro 2004. But for one England fan in the crowd that night in Lisbon, things had taken an unexpectedly bright turn.

Claiming he caught the ball when it came towards his lofty vantage point, he sold it to the highest bidder for £18,700.

But instead of choosing a conventional auction house to make the most of his good fortune, he turned to online auction site eBay.

In the five years since made its first sale, it has levered its way into the British way of life, both through sheer weight of numbers, and through the tales it throws up. Everybody knows somebody who has bought or sold on eBay; everybody knows a bizarre eBay story.

Whether it's people selling their virginity, Britney Spears's used bubble gum or a bucket of water, or whether it's the celebrity users from Cherie Blair and Sir Paul McCartney to Johnny Depp and Cameron Diaz, eBay is a haven for the odd-ball, the curious and the downright weird.

The site, which marked its fifth anniversary with its first television advertising campaign earlier this month, has around two million items for sale at any one time in the UK, and reached the 7.5 million users mark in August. It is the largest online market place, and just under a third of regular Internet users pay it a visit in an average month.

But what is perhaps most unusual about eBay, is that it is all based on trust. Buyers will bid for an item and, if they are successful, they send their money. The seller then sends the goods. Or not. If the goods don't arrive, most of the time the buyer's only recourse is to register their unhappiness. Surprisingly, most of the time it works.

"What eBay has done is caught the imagination of the British public," says Jamie Parkins, account manager at eBay's London headquarters. "There has always been the quirky side, the charity stuff, the celebrity auctions, and that generates a lot of fun about the site.

"And one of its core strengths is this idea of community, buyers and sellers who help each other out."

It is this community which prevents eBay from descending into a dog-eat-dog world. Buyers are encouraged to post their feedback on a seller, so when the seller next appears, prospective buyers can look at this feedback and decide whether it is sufficient to trust him.

It doesn't always work. Earlier this week a 17-year-old boy from south Wales appeared in court to admit 21 charges of fraud, with another 64 taken into consideration, after he sold non-existent items on the site, funding a lavish lifestyle which saw him hire limousines for nights out and took him to New York for the weekend. Altogether, he made around £46,000.

The site promotes the use of the PayPal system, which offers protection on purchases over a certain value, but ultimately it relies on trust, and the number of unscrupulous traders being far outnumbered by the number of smooth transactions.

'The percentage of cases like that is extremely small," says Mr Parkins. "We have a saying that people are basically good. The community will always rally round and will report these customers and bring them to our attention.

"The feedback system is one of the reasons why it stands head and shoulders above the competition. Buyers can have confidence in what a stranger is selling, and make a judgement based on their behaviour in the past."

eBay started in 1995 in the United States, as the result of a conversation between Pierre Omidyar and his wife, who collected the Pez sweet dispensers. She mentioned how it would be good if she could expand her collection over the Internet, as well as talk to other collectors, giving Omidyar the idea of setting up a central point to buy and sell unusual items.

The name came from his consultancy company, Echo Bay Technology Group, the first item traded was a broken laser pointer. It now has 114 million customers in 29 countries.

Sellers can put items up for auction, with each sale given a time limit, but can also offer to sell at a specific price without going to auction. But for some buyers, the excitement of the auction is part of the appeal.

"It is a thrill. It gives you the feeling of dabbling in something with a bit of risk, but without being too threatening," says Dr Joan Harvey, expert in consumer psychology at Newcastle University.

"It is an interesting phenomenon because it is self-policing. You can get stung, and there is not much comeback other than that people can be bad-mouthed, but it seems to work very well."

As well as being a boon to those who either don't want to or can't leave the house, it also taps into the obsession with what just a few years ago would have been thrown away as junk. Now, everyone thinks there may be something valuable in their attic. On the other side, everybody is looking for a bargain.

"Ten or 20 years ago, people didn't know what to do with what they didn't want. Now they can put it on eBay," says Dr Harvey.

"It has got a bit of a thrill, a bit of a risk, you can do it from home, and the fact you can't touch it before you buy gives you a bit more anticipation."

Ten eBay facts

* The most expensive item sold on eBay was a Gulf Stream jet, which cost $4.9m. The most expensive item in the UK was Lady Thatcher's handbag, which fetched £103,000.

l The UK site sells a CD every 11 seconds, a piece of women's clothing every 20 seconds, a vehicle every two minutes, and a football shirt every five minutes.

l One of the five most complete mammoth skeletons, nicknamed Max, sold for £61,000. It was 50,000 years old and weighed 250,000kg.

* Fireworks, drugs, guns and lock-picking equipment are banned, but sellers have put their virginity, their wives and their friendship up for auction.

l A Scottish landowner used eBay to find £10,000 worth of china stolen in a burglary. It appeared on the site ten days after the burglary, and the seller was charged with handling stolen property.

* 13-year-old Andrew Tyler from the US ran up a £2m bill bidding for items including a replica Viking ship and a Van Gogh painting, before his spree was halted by eBay. The sales were cancelled.

* Around 10,000 individuals or businesses are estimated to make a living from eBay in the UK.

* About $1,000 worth of goods are traded on eBay worldwide every second.

* There are more than 50,000 product categories, with more than 25 million items on sale worldwide at any one time, with 3.5 million added every second.

* Items for sale yesterday included a kangaroo scrotum, rings which allow people to live forever, and a year's friendship with a 16-year-old rocker.