Marks and Spencer gambles on bringing internet age to the shop floor

Bronwyn – proudly patting herself down and establishing that under her clothes and smart, hot-pink anorak it's just the "bra and knickers" that have been bought at her favourite store – says: "I'm an M&S lady."

The 62-year-old retired social worker was one of hundreds of shoppers crowding the aisles of the new Marks & Spencer superstore at Cheshire Oaks in Ellesmere Port when it opened last week. With a shop-floor area equivalent to the size of 11 Olympic swimming pools, the vast store – codenamed "concept 11" – is M&S's best crack to date at merging the worlds of physical and online shopping.

M&S is trying to please loyal shoppers like Bronwyn who arrive at its stores armed with mobile phones in their handbags that have more computing power than the average PC of a decade ago. "I'm one of the older generation – we get called silver surfers – who are switched on to modern technology," she explains.

With the internet now part of the fabric of modern life, M&S's digital guru Laura Wade-Gery, is firm: "The high street is not going to stand still so we know that we can't." The executive, who was hired from Tesco last year, is behind the retailer's growing arsenal of interactive shopping technology. "How do we use the internet to reinvent the store?" she asks. "It's as big a mission as that."

In the Cheshire store, customers are invited to use "browse and order" hubs kitted out with giant touchscreens that look like they have been stolen from the Teletubbies. The latest clothing lines and home fashions are beamed from 70in "inspirational" displays, with additional backup provided by assistants prowling the shop floor armed with holstered iPads, ready to plug the gap between the thousands of products hanging on the rails and those out there in cyberspace.

The striking store, which has a curvy wooden roof made of "glulam" (glued laminate) and hemp walls, might be M&S's greenest to date, but in the six long years it has taken to come to fruition it has increasingly been argued that big stores are growing obsolete, as shoppers defect to the virtual high street.

M&S boss Marc Bolland admitted at the opening that if he could have turned back the clock, the monster store would have been "a tad smaller". At 151,000 sq ft it is unlikely M&S will ever open such a large branch again. But with a catchment of 1.3 million people and £4bn of local retail sales to go after, Bolland insisted it was not just a large store, but rather "a shopping experience".

The shadow cast by the internet and now mobile shopping has spawned retail industry buzzwords such as "multichannel" and even "omnichannel", which attempt to describe how customers increasingly use both store and websites in tandem. Jargon aside, retailers find that the more channels their customers use, the more they spend. M&S says shoppers who shop on its website as well in its stores spend four times as much; throw smartphones into the mix and they spend eight times as much.

To that end Wade-Gery recites the Coca-Cola Company's famous goal to be "within an arm's reach of desire", which helped it conquer the soft drinks market in the 20th century: "We have to provide more ways for consumers to access M&S."

The retailer is spending £150m to upgrade its website, because for all the technical jiggery-pokery and free Wi-Fi at Cheshire Oaks, antiquated systems mean it still takes up to five days for items ordered in store to arrive. With multichannel sales accelerating in the second half of the last financial year, Wade-Gery suggests she is already making an impact on the retailer.

Andy Morrey, M&S's first e-commerce director, who has since founded retail consultancy eNova, says the high street is responding to consumer behaviour, not the other way around: "There is no point launching a service or app just for the sake of it," he explains. "It won't work unless it addresses a consumer need." A McDonald's app is reported to have been little used "because nobody needed an app to find a McDonald's".

In his subsequent job at Argos, Morrey masterminded the launch of "click and collect", a service now taken for granted by shoppers: "Nobody else had done it and the industry was very sceptical about whether it would be a success." Multichannel retailing is still in its infancy, he adds, predicting that faster broadband speeds and 4G will trigger more change.

Most of M&S's shoppers are aged over 40, and some analysts argue the internet is less relevant to it than chains with a younger clientele. Wade-Gery, however, remembers a recent focus group in St Albans when a 75-year-old woman held forth on the merits of Groupon. "You have to be really careful not to stereotype people," she says, adding that half of women aged 55 to 65 own a smartphone, while one in three has a tablet computer.

The multichannel effect has certainly helped John Lewis, M&S's arch-rival for the hearts of middle England's shoppers, during what has been a prolonged high street downturn. Conlumino analyst Neil Saunders says online sales will grow 13% this year, against a retail market that will shrink by about 1%. "If you are not online you can't tap into these seams of growth," he says.

Saunders thinks M&S has more pressing concerns to address than getting its "bricks and clicks" act together. Last year its share of the womenswear market dropped from 10.9% to 10.4%, due to a combination of tough competition and buying mistakes that resulted in shortages of bestselling lines. "M&S is still the biggest but each year its lead is dwindling," he says.

Back at the store, Carole, clutching outfits for her baby grandson that she says are a steal at £8, nails the problem: "My only complaint would be when I walk in the womenswear department and see the same style they have done for the last two years – it's just in a different colour."

M&S's new autumn fashion ads, which will be shown for the first time this week, aim to highlight the retailer's "style credentials". The ads will feature relatively unknown models as opposed to the store's usual cast of "faces" such as Twiggy and Lisa Snowdon. Investec analyst Bethany Hocking describes the change as "high risk".

M&S's long-serving fashion supremo Kate Bostock is leaving at the end of this month, and her part-time replacement Belinda Earl, the former Debenhams boss, is due to start work tomorrow. Earl helped establish successful in-house brands under the Designers at Debenhams label and she is doing the same with M&S's six main womenswear brands, including Autograph, Per Una and Limited, which are felt not to be distinct enough. "I don't think online is the holy grail for M&S," continues Saunders. "It's a piece of the jigsaw but not the whole picture … product comes first."

After all, not all M&S shoppers are ready for cyberspace. Pensioners Elaine and Maureen, trying out the hand creams in the store's beauty hall, prefer shopping the old-fashioned way. "They are too complicated, those posh phones," says Maureen. "I don't shop online, I want to see it first." And she admits to scouring the sale racks for bargains: "I like Per Una, but it's a bit pricey."