Conventional wisdom dictates that a female celebrity's worst fashion faux pas is to turn up to an event wearing a dress that has been worn by another, thinner celebrity before. The "who wore it better?" feature, a standby in celebrity fashion magazines, has rendered the "repeat dress syndrome" even more of a bête noire. Yet a certain designer appears to be changing that rule.

When Drew Barrymore stepped on to the red carpet in Los Angeles this week for a film premiere, she wore a purple satin dress that looked familiar. Not only had it been worn before by at least two other prominent celebrities, but, with its mid-calf cut and tight cut, its style is very associated with a very thin celebrity who also happened to be the designer. It was, of course, another dress designed by Victoria Beckham.

This dress – worn recently by both Beckham herself and singer Katherine Jenkins – has been widely deemed a success for Barrymore by the catty celebrity magazine world despite its familiarity. It is seen as yet more proof that Beckham, after just three collections, has reinvented herself as a real fashion player.

Once she was credited, if that's the right word, with coining what became known as Wag style, all hair extensions and hotpants. Now she is associated with a specific style of tailored designer dresses. Her association with the look has not put off her fellow celebrities. If anything, she acts as an improbably successful advert. Stella McCartney, Brooke Shields and Dannii Minogue have been photographed wearing the distinctive Beckham dresses recently. Elle Macpherson loves hers so much she was pictured wearing them three days in a row.

Nor is it just celebrities who wear them: Netaporter, the luxury fashion website, and Selfridges have said that Beckham dresses sell out "instantly", despite their £850 starting prices.

While the rest of the luxury fashion market barely stumbles on, with worldwide sales down, according to modest estimates, at least 17% this year, Beckham may be the phoenix rising from the ashes of the economy. The day the US celebrity press was cooing over Barrymore's dress, it was reported in the New York Times that Versace was cutting 26% of its worldwide workforce after projecting a loss of $45m this year.

Beckham, who has happily conceded that she "can't draw" but "knows clothes" has been canny in her choice of fashion influences, opting for designers who are respected by fashion insiders and have cuts that flatter women's curvy figures.

For the past few seasons her dresses have prompted comparisons to Roland Mouret. For next season she seems to have moved on to Azzedine Alaia in terms of influence, with slightly girlier cuts and A-line skirts. They have the fashion consciousness that gets applause from the industry, combined with the body consciousness that Beckham still prefers.

"I don't want to make dresses that will date. I've always been about clever buying," Beckham said when she launched her label last year.