From CBS' peanut-posting Jericho watchers to Cadbury's Wispa-holics united, it's become practically impossible for brands to ignore the power of fan communities.

Many companies, in fact, have found that by tapping into these fan clubs, they can generate positive word of mouth and build an incredibly dedicated network of advocates.

"The fans are not a group you can ignore," says Steve Sansweet, Lucasfilm's head of fan relations. Keeping fans in the loop - both online and off - has been a ...