For years, if you were out doing your last-minute Christmas shopping, retailers and marketers treated you as a helpless speck they could drag inexorably into a sinister-sounding “purchasing funnel”.

The analogy is attributed to an early marketing guru called Elias St Elmo Lewis. (Tip for budding ad-people: if your surname is a plain one make sure you acquire a striking middle name.) In 1898, Lewis was said to have modelled a linear “journey” for the heedless consumer, from awareness, to interest, to desire, to action. Ker-ching.

This was a simpler time, though, when shopping almost always did involve an actual journey from home to store and back again.

The template is long overdue a revamp, if for one reason only: technology has shaken up the old relationship between retailers and shoppers.

The purchasing funnel was part of the same thinking that lay behind the creative marketing of department store impresario Harry Gordon Selfridge. His London store used to offer Christmas puddings to bus drivers, tempting them to stop on Oxford Street where passengers could step off the bus and into the shop. The same principle of turning desire into action fuelled Harrods’ advertising of its post-Christmas stock clearance, first held in the 1890s, as a cornucopia of bargains that “embrace practically every human need in fashions, furnishings and foodstuffs”.

The principles have been refined over time. Marketing geeks can pick from the “Howard-Sheth theory of buyer behaviour”, to “consumer decision journeys” and “customer journey maps”, among many variations touted by consultants and academics. Each claims to offer clues to sellers about how to divert the shopper to their door.

Retailers have occasionally resisted the crudeness of marketing and discounting. “I am utterly convinced that before long [surplus stock] sales will be regarded as an old-fashioned anachronism, a stunt . . . that was just plain stupid,” wrote retailer Stafford Bourne in the Financial Times in 1966.

Bourne was right about the potential damage caused by an obsession with discounting. US retailers warned this month that post-Thanksgiving knockdown prices have lasted longer and cut deeper than at any time since the financial crisis, potentially jeopardising their margins. Yet his Bourne & Hollingsworth store on Oxford Street closed in 1983, while discount sales — from Black Friday to China’s Singles’ Day — continue to expand.

Meanwhile, the customer journey has become increasingly twisty. This Christmas, I have browsed for and bought presents on foot, online, on the phone and via email, while in the office, in bed, at the breakfast table and in the train to and from work. I’ve clicked-and-collected, picked up from the Post Office, ordered for delivery to home and office, and bought gifts from stores, stalls and Selfridges itself. I have hung up, buffered, suffered delayed delivery, and resisted a variety of marketing pitches that would have overwhelmed Lewis’s basic funnel.

Some of these abandoned journeys used to be put down as a “failure to convert” to a sale. That is too simple, according to Claire Tsai, a marketing professor and behavioural expert at Rotman School of Management.

She and fellow researchers have examined how changes in lifestyle, knowledge, technology and the structure of retailing have also changed how people shop. For instance, thanks to online research, customers are now often better informed about products than retailers’ own staff. Social influence — the passive advice of peers, through reviews, and the active search for friends’ opinions about products — has also changed behaviour.

The researchers came up with a new model that puts shopper satisfaction at the centre. They also identified 12 different journeys, some of which — shopping for entertainment, say, or for research — may not yield an immediate sale but still point to the same final destination. Prof Tsai told me retailers should be working out how and where “to intercept [shoppers] when they are ready to be intercepted”.

I like the idea that the old-fashioned customer journey is no longer just a series of steps, but a “configuration of states”, in which some consumers are “exploring”, “validating” their decision, or just waiting.

It suggests that, even in the midst of Christmas commercialism, shoppers themselves have options about whether to advance or pull back. Unscrupulous salespeople and their social media intermediaries are waiting online to lure us in with new, often hidden, techniques of persuasion, of course. But the decision about whether to be sucked down Lewis’s funnel is in the hands of the smartphone-toting consumer as much as in those of the wily marketeer.

andrew.hill@ft.com

Twitter: @andrewtghill