Buying clothes online is a growing trend – now that a new generation of designers can offer celebrity style at top speed. Ian Johnston reports

Once fashion on the internet was a hard sell. Customers were reluctant to hand over money for clothes they could not try on or even touch before buying.

But, amid a slump on the high street, online fashion sales are soaring. Shoppers have belatedly embraced the idea, and the internet now looks set to do for fashion what it did for music: turning virtual unknowns into overnight sensations by providing a direct connection between designers and the public.

The internet shopping firm Asos, which stands for As Seen on Screen, has been the runaway success story to date. While online sales of clothing and footwear rose by nearly 40 per cent over the past year to £1.7bn, Asos saw an increase of 90 per cent, taking its turnover for the year to April to about £80m, largely because of a feature of the internet it was first to exploit.

Instead of seeking inspiration from photographs of models and film stars in fashion magazines and then searching them out on the high street, Asos's customers can buy complete outfits styled on the look of celebs such as Sienna Miller, Kate Moss, Jessica Alba or Victoria Beckham at the click of a mouse.

Nick Robertson, chief executive of Asos, said internet fashion was bringing style to the nation and beyond. "The biggest driver of internet sales is convenience. It is about 'Am I going to get to Oxford Street in 12 minutes and get back in my lunch break? No'. It is compromising the ability to try on clothes for the convenience of buying online."

The newest entrant into the virtual world is, which has made the esoteric designs of the London market – as worn by celebrities such as Mischa Barton and Paris Hilton – available to a global market for the first time.

The fame of Portobello Road as a destination of choice for the fashion insider has created a wave of interest across the world at the news its designer wares are available online. Shoppers can even haggle with the virtual stallholders. Lisette Cooper, one of three sisters behind the site, said: "We haven't even done a proper launch of the site. It went live probably two weeks ago and it's massively taken off.

"We have had loads from New York and people from Russia, Sweden and Kuwait. Portobello market is a real hub of fashion talent. Celebrities often go down there and buy something, so it's got a little bit of kudos."

One of the designers hoping to benefit is Ducie Keam-George, who has her own Ducie brand and sells on both the Pret a Portobello and Asos websites. She said that, while it might take a year for major stores to get a design into the shops, this time lag could be reduced to a few weeks by operating as an independent.

Meanwhile, the internet social network MySpace launched a fashion site last year, which has already attracted more than 110,000 members. The singer Kate Nash, perhaps with an eye to potential crossover markets, was one of the first to join and has shot a video for the site showing her trying on clothes in Los Angeles.

Andrew McClelland, director of business development at the internet selling industry body, Interactive Media Retail Group, said: "From the retailers' side, we are starting to see much more innovation. They are accepting the fact that shopping is a fairly tactile experience and increasing the quality of graphics they use. You can use the zoom facility to look at the weave of the fabric, the stitching and details without actually touching it.

"What we are starting to see now is retailers embedding videos on their website – Asos does it, Next does it – to illustrate to customers how that product fits and how it flows when you are walking."

The success of internet fashion might be seen as a threat to the high street, but few were willing to forecast its demise. However, Mr Robertson spelled out where he sees the future. "Ask a 10-year-old where they are going to prefer to do their shopping, and I think they will say online."