My name is Jane Perrone and I am addicted to eBay. So it came as no surprise when the online auction site announced last week that it provided a marketplace for goods worth £3.37bn in the first three months of 2003, doubling its net income to £66m.

I am one of the 68.8 million registered users who spend large swathes of time buying and selling via the net, allowing eBay to cream off such a healthy profit.

I blame my sister for my eBay habit. A couple of years back, she emailed me details of some kitsch trinket she fancied as a birthday present: I registered, bidded, won the item for a ridiculously low price, and was instantly hooked.

The UK head of eBay, Douglas McCallum, has predicted that half the UK's online population will be using the auction site to buy and sell goods within five years. So are we about to become an eBay nation?

eBay has managed to transfer seamlessly to the web the bargain-hunting spirit that packs them in at car boot sales and popularised the TV show called, er, Bargain Hunt.

But it is the millions of users selling everything from mobile phone covers to sports cars that have made it an online behemoth. eBay allows people to indulge in their strangest obsessions, confirming the truth of the adage "one person's junk is another person's gold".

I recently compared notes with another addict, who, despite appearing to be a sane individual, said he went through a stage of bidding for retro mermaid figurines for his fish tank, "but only the good quality ones". Someone else told me that their father recently purchased 20 chip pan baskets for no apparent reason.

I first realised I was addicted when I stayed up till the wee small hours waiting to make a last-minute bid on a pristine 1960s Luton Town FC Subbuteo set. I can easily spend an hour flicking through pages of retro melamine ashtrays, and I don't even smoke.

I justify my addiction in many ways: it's useful for getting rid of unwanted Christmas presents (lava lamp anyone?), I can always find unusual birthday presents for people, and the money I spend goes directly into someone else's pocket rather than being deposited in a retailer's cash till.

I'm the kind of person (read: sucker) that another addict, who prefers to be referred to simply as "Gary", makes money from.

He started using eBay when the first Lord of the Rings film came out. "I found an old 1970s Tolkien board game in my loft. I thought I'd cash in on publicity. It sold for £160 and I was hooked," he says.

Gary spends about 10 hours a week on the site and made £200 profit on £700 turnover at the height of trading last summer, even buying stock from real auctions to sell on via eBay.

Gary is used to dealing with a global audience for his sales. "I had a New Yorker who was adamant that London was a district in Brooklyn and he wanted to save on shipping by driving over to collect. What do you tell them?"

eBay's triumphs in the UK are echoed around the world. It is the only online auction site to garner a truly international user base (it has 20 country sites) and become a high-recognition brand with a loyal army of more than 30 million active users.

How? The key to eBay's success is that, on the whole, it works and people trust it. The site's feedback system - which allows buyers and sellers to rate other users - allows you to ensure you only trade with other users who have a good track record, and where disputes do happen, eBay is happy to arbitrate.

Things do go wrong, though, and the stakes can be high. People tend to throw aside the normal checks they apply when buying or selling high value items. Tom Wykes, a printed circuit board designer, spends about an hour a day on eBay. He sold a Land Rover worth more than £5,000 to someone in the US, but the buyer kept him waiting for three months before pulling out from the sale.

Ian Donegan, an advertising executive, has bought and sold around 300 items without any major hiccups. But he is aware of the dangers of impulse bids. "Surfing eBay late at night after getting back from the pub is not to be recommended and can be very costly," he notes sagely.

None of the fellow addicts I spoke to are planning to give up their auction obsession: in fact, I regularly add to our number by recommending that people have a look on eBay before splashing out on a new mobile phone or laptop. Personal recommendation is part of the reason why, along with Google and Amazon, eBay has earned a place as one of the holy trinity of essential consumer websites in the largely cheerless world of the dotcom downturn. And I can stop anytime, honest.