A recent report on European online consumers found that around 60% of users take part in social networking activities, including interacting with online communities; reading or writing blogs and customer reviews; listening to podcasts; and setting up RSS feeds.
Pickering suggests that this rise in social media has shifted the control of information from big business into the hands of the consumer, who can make or break a brand by word of mouth.
He warns that all marketers need to establish a new dialogue and take advantage of social media to engage with consumers, because they now hold the power.
He said: "Instead of listening to advertisers, they increasingly refer to their peers in online communities when deciding what to buy. Social media is becoming the voice of the consumer."
According to Pickering, all companies need to sit up and pay attention, and follow the lead of Google in its acquisition of YouTube, Yahoo! in its purchase of Flickr, and News Corporation's acquirement of MySpace.
Pickering said: "Social networking is changing the way we publish, consume and share information. It is profoundly affecting the way we think -- or should think -- about marketing and public relations.
"Forums and blogs and other kinds of social networking are here to stay. We dismiss or underestimate them at our peril."