The Alexa Factor

She is the secret of Mulberry's success, a cover girl guaranteed to shift magazines, and a fixture at the catwalks. How does Alexa Chung do it?

Having a bag named after you is one of fashion's highest accolades reserved for the world's most glamourous women.

The Kelly was named after Grace, the screen siren and princess of Monaco, and the Birkin was created in homage to Jane, Sixties sex bomb and muse to Serge Gainsbourg. And then there is the Alexa, made by the luxury leather goods label Mulberry, and named after Alexa Chung, a 26-year-old from Privett, Hampshire who has taken the world by storm with her winning smile and throaty witticisms.

When Mulberry this week announced a huge 79 per cent increase in sales, their success was laid at the feet of the model, muse, and television presenter, who last year lent her name to the leather satchel that comes in black, tan, purple and leopard print. The £700 bag sold out several times, and had a waiting list of 9,000, prompting the company to extend its Somerset factory to match demand.

Chung's characteristic good taste, sartorial flair and style-set savviness – not to mention high cheek bones – have made her marketing gold when it comes to moving merchandise and making money. "All those women you see right now in thick-rimmed glasses, wearing ankle socks with loafers and carrying satchels? Alexa influenced them all, whether they realise it or not," says Jenny Dickinson, deputy editor of Elle, which features Chung on the cover of its current issue.

"Only Kate Moss is on a par with her in terms of influence on commercial trends. By not appearing too keen or too in-our-faces, Alexa's taking the perfect approach."

Brand Chung has become powerful enough to make her a fixture in the front row – she was at home next to Vanessa Paradis, Claudia Schiffer and Sarah Jessica Parker at Chanel's spring/summer 2011 show in Paris on Tuesday – but it would be wrong to dismiss her as an It-girl. Chung has A-levels and a conscience. She's a vegetarian and a DJ; she speaks out against sweatshops and the more inane aspects of popular culture.

After cutting her teeth as a catalogue model, Chung's big break came in 2006 when she was offered a presenter job on Channel 4's music magazine programme PopWorld, where she became known for her modish ennui and sarcasm-laden interviews. "You do a lot of things mediocre," she told the American girl group the Pussycat Dolls. "But what are you worst at?"

From moving to New York last year to host her own show for MTV, to designing a range of clothes for American company Madewell, which she unveiled during Fashion Week last month, Chung has been careful to busy herself with more than just the party circuit. In a rare mis-step her MTV show was cancelled after its first series, but this month sees her taking over as host of MTV2's alternative music show Gonzo. It's the

latest addition to a CV that includes a slot as contributing editor at British Vogue, co-presenter (with designer Henry Holland) of Channel 4's fashion show Frock Me and the star of numerous fashion ad campaigns.

Brands know that with her face – an idiosyncratic hereditary mix of her three-quarters Chinese father and an English mother – come customers, cash and most importantly, cool. It's all summed up in the bag which bears her name: it looks good, it's practical and hard-wearing but has an aura of glamour and a quietly in-the-know charm. It's expensive, and it's a byword for the In Crowd.

On the surface, Chung has all the usual hallmarks of a London party girl – the rock-star boyfriend (Alex Turner of The Arctic Monkeys), the celebrity friends (models Daisy Lowe and Agyness Deyn, to name a couple), the face, the figure, and the wardrobe. But dig a little deeper and there's much more to her than that.

"I can't overstate enough how fun and funny she is," says a friend from her teenage years, who met Chung through her involvement in his sixth form fashion show. "She was stunningly beautiful of course, but she was also refreshing and engaging. She took such an interest in everyone, from the jocks to the geeks. When we all saw she made it on to TV, it was no surprise. She's really special, a hugely accomplished, practically perfect person."

It might do to add a disclaimer to this gushing praise. The acquaintance, who preferred not to be named, was at a single-sex boarding school at the time of meeting Chung, and would perhaps have fancied a postbox had it shown him any interest. But his description tallies perfectly with all of the interviews, face time or red carpet chats Chung has ever given. She has a star quality which attracts fans, as well as a pleasant ordinariness, which keeps them in her orbit.

Chung's conquests in the fashion world, for example, includes the not-so-easily captured heart of Chanel designer Karl Lagerfeld, with whom she spent a day in front of the cameras for a 2008 documentary. Since then, she has become a fixture at Chanel events and carries off the label's signature gamine girlishness with breezy aplomb.

"She has that French knack of being fashionable but never looking like she tries too hard," says Kay Barron, Fashion News and Features Editor at Grazia. "Her hair is always a bit messy, her make-up is minimal. Whether she's in head-to-toe Chanel, Louis Vuitton or Topshop, she doesn't make fashion scary for anyone and gives the impression that if you borrowed her outfit, you'd look as good as her (which of course you won't). But that's what makes her the perfect style icon for fashion magazines and designers alike."

So try as you might to avoid Alexa Chung, you're not likely to manage it. And try as you might to write her off, resent and dislike her, if you're lucky enough to come into her orbit, you're not likely to manage that either. As marketeers and magazine editors circle like sharks, a bag named Alexa is surely only the first step in the rise and rise of Miss Chung.