A large majority of influential consumers do not regard advertising or social networks as being "credible" sources of information, according to new research from Edelman.

Based on a survey of "opinion leaders" in 20 countries, the PR firm reported that just 17% of its participants viewed advertising messages as being trustworthy, with social networks on 19%.

While the company’s panel had highly specific characteristics – such as a college education, high earnings and a keen interest in news content – it is also a very attractive demographic for many brands.

More positively, large numbers of this group regarded regular communications as being a hallmark of the companies they respected.

It may be the case that survey respondents more generally don’t like to admit that they are influenced by advertising.

What makes this study unusual is that it sounds a note of caution about social networks, which are currently popular with marketers across most product categories.