Proving that not all interactive campaigns need to be aggressive, Cadbury has employed Facebook to serve as a listening post for the candy-maker, which decided to bring back a chocolate bar called Wispa after a digital petition highlighted demand for a treat that had been discontinued four years prior.

In a rather simple campaign, the Cadbury Schweppes food conglomerate, which made Wispa, used Facebook groups to listen to its consumers. The result: nearly 14 thousand Facebook users signed on to bring back Wispa, with some Wispa-lovers going as far as to post old TV commercials for the discontinued candy bar.

"We have noticed the web interest for some time, and the consumer passion has undeniably swayed our opinion to relaunch Wispa," a Cadbury official told The International Herald Tribune. "This is the first time that the power of the internet played such an intrinsic role in the return of a Cadbury brand."

Cadbury plans to bring Wispa back in October.