Trump succeeded last week after winning narrowly in a number of Midwestern states – despite polls and forecasts consistently predicting that Hillary Clinton would win.
The outcome has been compared by commentators to the UK's EU membership referendum in June, when polls similarly failed to pick up on the degree of anti-establishment sentiment in the country.
Mark Lund, chief executive at McCann Worldgroup UK, said that Tuesday 8 November may be remembered as "the day the market research industry suffered a fatal wound".
He added: "The polling got it badly wrong and if polling is that inaccurate, you have to ask the question about whether the tools that marketers use to discern the shape of the world are much better."
Marks & Spencer executive director customer and marketing Patrick Bousquet-Chavanne echoed this, saying the "predictive models came very short", and adding: "We have to make sure we’re looking at our own analytics very closely to make sure they’re rigorous."
Meanwhile, Heineken UK head of marketing Cindy Tervoort said the result showed the need to support data by directly speaking to as many consumers as possible.
Lost for words
Mark Wrighton, vice president EMEA at ad tech company Impact Radius, said that marketers would need to heed the election result, since "anything that threatens global stability or creates significant uncertainty for markets and consumers is destined to impact marketers from a budget perspective."
But with uncertainty about the shape that Brexit Britain and Trump’s America will take, marketers broadly told Campaign that their marketing plans and budgets would not be changing.
Many in the industry are in shock, however; a chief marketing officer at a major FMCG company said the issue was "too deeply personal to provide a coherent response", while the brand director at a leading financial services company said: "I am not often lost for words but I am this time."
But Lund said that if either result seemed surprising, it was because those working in the media were "intent on telling themselves it couldn’t really happen". This phenomenon, he said, could also be seen in the ad industry, and meant that many agencies were at risk of losing touch with the mood of the country.
Lund’s comments were supported by marketers who warned brands that failed to understand their audience were headed for irrelevance.
Morrisons brand and communications director Mike Hoban added politicians needed to learn from marketers that "you’re only successful if you truly listen to your customers."
What are the people saying?
Trump’s rhetoric in the campaign, about making the voices of ordinary Americans heard, bore similarities to Nationwide’s current campaign, "Voice of the people", which features a series of little known poets reading poetry about their life experiences.
Nationwide's chief marketing officer Sara Bennison said the campaign had emerged from the observation that in the financial sector, people did not feel listened to – a problem she said was just as problematic for established banks as for politicians such as Clinton.
Bennison added that Trump and Brexit had succeeded because they were "about big, galvanising arguments that were repeated. People do still connect to the big simple message again and again."
Like Brexit, Trump’s presidency is troubling for its potential to cause "big economic waves" that could make it harder to attract investment, Lisa Wood, chief marketing officer at Atom Bank, said.
But it should also be a wake-up call to brands that "we’re moving to a phase where people are demanding more transparency, demanding that they’re heard. Marketing cannot tell people what to think."