The core of corporate social media practice is that customers trust their peers and thus if you enable them to tweet or write blog posts about your products or services, it will help boost sales.

In 2006 the Edelman Trust Barometer found that peers were the most highly trusted group. Richard Edelman, the head of Edelman, the largest privately held PR group, dubbed it the Me2Revolution.

But trust in peers has fallen considerably. From 68% in 2006 to 47% – a further decline of 4 percentage points in the past year.

Steve Rubel, Director of Insights at Edelman speculates on the reason for the decline:

…as more of us join social networks, there’s been a devaluation in the entire concept of “friendship.” A separate survey found that people don’t know 20 percent of their Facebook friends. Consider that “unfriend” was Oxford’s word of the year for 2009.

Or more likely: familiarity breeds contempt.

There is a lot of data to dig through in the latest trust barometer findings. But this particular piece of information about the growing lack of trust in peers, and the rise in the trust of accredited experts is very interesting.

You might assume that this data would affect how companies promote their products and services. Since trust in peers is falling, investing heavily in social media might not be the best approach.

The rise in experts is interesting. Mr Rubel writes:

…the Trust Barometer revealed rising confidence in credentialed experts (70%, an increase of 8%). This is a trend that began last year. In addition, for the first time we looked at the credibility of technical specialists inside a company. Trust in this group is off the charts (64%). This hits home the need to identify those with expertise inside a company who can engage across different channels, many of which today are digital – or will be soon.

This is exactly what Jon Iwata and his team are trying to do at IBM, to find those experts internally and help them engage across different communications channels.

In many ways this trust in experts goes back to what has been known for a long time in the advertising business, that people pay attention to accredited experts. After all, 9 out of 10 doctors that smoke can’t be wrong.

[Cross-posted at Silicon Valley Watcher]