More evidence of the power of social networking as it relates to PR. In case you missed it, Cadbury

  Schweppes is bringing back a defunct brand (the Wispa candy bar) because social networkers demanded it. Cadbury, better known in the U.S. as the maker of Snapple and Nantucket Nectar, discontinued Wispa in 2003—and almost immediately fans sprung up asking for it back. In June, two chocoholics stormed the stage during Iggy Pop’s set at a UK music festival and held up a “Bring Back Wispa” banner. But what really tipped the scales for Cadbury were the nearly 14,000 Facebook members who have joined the online campaign to revive the product. You can read more about it here.

Cadbury’s response is a perfect example of why tracking customer sentiment– using search engines and services like Cymfony and Nielsen Buzzmetrics– and responding to consumer sentiment has become a top priority for brands and PR pros.

This was certainly a good piece of news for Cadbury to counteract the negative press it’s been getting lately over being forced to delay or even cancel the sale of its beverage division due to the global credit crunch.

Above is a great B2C lesson, but also watch out for this on the B2B front. The WSJ recently picked up on the emergence of professional-level social networks that enable executives to interact with peers. Just as Facebook and Bebo are driving change in the consumer sector, social networking is quickly seeping up into the B2B world. As one obvious example, pharmaceuticals companies are going to need to monitor these sites for what doctors are saying about new drugs.

Guest blog written by Matt Purdue, Senior Analyst for Peppercom.