Commissioned for the Guardian Changing Advertising Summit, the survey found that 86% of marketers consider big data was changing the marketing function with 53% said it was now ‘very important’ and 62% saying their job had already changed as a result.

The survey also found that marketers felt that big data would see consumers expecting more targeted messages being created but only 30% of marketers thought they were sufficiently qualified to handle the challenge.

When questioning consumers, the survey found that despite knowing that their activity was tracked by companies, 47% of consumers had a poor understanding about what was being collected, although most understood data would be used for targeting them with offers.

The research revealed that the majority of people weren’t always convinced by the personalised offers they received: only 34% said they were ‘happy’ when companies suggested products for them based on the information they knew about them.

The research also found that 81% of consumers said they were more likely to give their business to companies that used their personal data appropriately and the survey comes at a time when the government’s midata initiative is about to be introduced.

Colin Strong, GfK’s managing director for business & technology, said: “If midata legislation was implemented it would allow consumers to manage much of their own personal data so in some instances they could choose what to share with brands. This would significantly change consumer sentiment and the dynamics of the market place, giving people what they say they want, more control over their personal data.”