'Citizen marketers' can severely damage a firms reputation, small businesses have been warned.
According to Caroline Waters, director of employment policy at BT, the rise of the internet and social networking websites means that bad news about a company can spread fast.
However, the opposite is also true and if people like a product a company is offering, firms can realise massive benefits, she added.
Ms Waters said: "Someone who doesn't have an investment but just loves the product is ten times more valuable than all of the millions of pounds of marketing that a company can buy.
"That's the power of technology. We have to get used to understanding how to use it."
Ms Waters also believes that IT will change the way that firms work as well as what they do.
Recently, Trades Union Congress (TUC) general secretary Brendan Barber, called on firms to embrace flexible working to help them through the current economic downturn.
