While marketers are accelerating their use of AI, many have been left counting the cost of misleading or inaccurate AI insights, which have lead to their business losing revenue, says new research from intelligence firm, GWI.

Its poll of over 150 UK marketers showed that over half (55%) have made significant business decisions based on AI-generated insight, which later turned out to be wrong or misleading.

GWI warns that marketers’ confidence in AI-generated insight is outpacing the discipline to verify it, creating a gap that’s already creating significant costs for brands. Almost a third (29%) say trusting AI has led to financial losses for their organisation, while 35% report it creating customer complaints and a further 29% blame the technology on reputational damage.

“Marketing teams are under pressure to turn insight into action quickly,” said Jason Mander, Chief Insights Officer at GWI. “But when an AI-generated answer informs a campaign or strategic decision, its accuracy matters even more than its speed. These findings show the business cost of acting on incorrect insights.”

The consequences also extend to day-to-day work and campaign results. Almost half (47%) say inaccurate AI outputs have forced teams to redo work, while 54% say it’s delayed decision making. Meanwhile, 17% say it has actually damaged campaign performance, rather than enhancing it.

The findings also raise questions about how consistently teams check AI-generated insights before they act on them; only 29% currently verify AI-insights “most of the time” the poll suggests.

“AI is only as reliable as the data behind it,” Mander added. “Verification means knowing where an insight comes from, how the underlying data was collected and whether it’s still up to date. These checks need to be built into everyday workflows, so that when an insight informs a campaign or business decision, there’s strong evidence behind it.”