In 2001, Procter & Gamble launched Tremor, which recruits teen word-of-mouth (WoM) marketers and followed up with Vocalpoint* for moms four years later. Realizing that customer recommendations are worth more in terms of sales than some forms of advertising, both Kraft and General Mills (# 3 and 18 on the list of Top Food Companies) are following in P&G's footsteps and have launched new WoM networks.

For General Mills, it is "Pssst . . . " - an online network that gives members the scoop on the latest product news and offerings. The site (pssst.generalmills.com) currently has 100,000 members after a quiet launch last month.

Kraft, meanwhile, kicked off Kraftfirsttaste.com, which lets consumers share the newest coupon and sampling offers, but also includes features such as a member spotlight, product reviews, discussion boards and a photo-sharing tool.

"Consumers today regularly look to each other for recommendations and reviews on everything from books to food to cars, so we wanted to have a platform that enabled and encouraged this type of interaction and engagement," said Gwen Gray, who heads consumer relationship marketing at Kraft.

Neither Kraft nor General Mills pays members to join, but once registered, customers can voice their opinions via blog posts, share online coupon offers and recipes, and test new sample kits via the mail.

Andy Sernovitz, author of "Word-of-Mouth Marketing" expects to see more packaged goods companies getting into the space: "We'll see more and more companies realize that word-of-mouth is not an accident. It's something you do as a core part of the marketing mix."

*BusinessWeek called Vocalpoint "a state-of-the-art method for reaching the most influential group of shoppers in America.