Retail’s worst kept secret is out of the bag. Former Marks & Spencer fashion supremo Kate Bostock has finally been confirmed as the new executive director of product and trading at online giant Asos. What does she bring to the party?

Bostock is one of fashion’s biggest names with eight years under her belt at Marks & Spencer, not to mention roles as George at Asda and Next.

Someone of that calibre will undoubtedly make sure that Asos’ offer remains strong in the face of its rapid growth internationally, and that it is as efficient an operation as possible.

It is also thought that she will help the etailer improve margins through enhancing its buying process, in particularly by increasing volumes, and ramping up its own brand offer.

“They don’t buy in huge amounts of depths,” says N+1 Singer retail analyst Matthew McEachran. “They sell hundreds of thousands of SKUs but the average volume is not huge. There’s a big opportunity there.”

Asos, which has set a target of hitting £1bn sales by 2015, is looking to match the global powerhouses such as Inditex and H&M as it expands. Currently H&M buys 15 times more in volume on lines than Asos. The etailer has three ambitions that it wants to achieve as part of its growth plan: becoming truly global, creating the most engaging experience and practising highly efficient retailing.

Bostock’s experience heading up some of the UK’s biggest fashion chains will help it achieve its third aim. She is described by one person who knows her as “a control freak, in a good way, who likes to take responsibility and is good at creating a vision that people can buy into”.

The move from a mid-market, high street stalwart like Marks & Spencer to a young, trendy etailer Asos has raised some eyebrows. One analyst asked: “Does Asos need help with its range? Is she too old?”

However, Bostock, who was placed by Flint Hyde in the Asos role, will not be at the coalface deciding what lines to buy. McEachran says: “There is no doubt that a design and buying team the size of Asos’ knows what product its customer base want.”

However, the jump from M&S to Asos is a big one and some believe that Bostock may need a period of adjustment.

McEachran says: “There’s a big question over how quickly she can integrate into what is a very different business culturally.”

It is no secret that Bostock and M&S boss Marc Bolland had a rocky relationship when he took the helm, but hopefully her transition into the Asos business will be smoother.

For Asos to pull in Bostock shows that, coupled with the hire of former Amazon boss Brian McBride as chairman last week, the etailer is becoming a global force to be reckoned with.