Employee communication through informal means works fastest and rumor mills always reach faster than any formal channel of communication. Grapevines has been always considered as a powerful communication network and as per wiki a study quoted in Forbes magazine concludes that 75 percent of employees hear about matters first through rumors on the grapevine.
Robbins states that rumors flourish in an organization because of three elements. They are a response to situations that are important to employees, where there is some ambiguity, and under conditions that arouse anxiety. From a management perspective, the grapevine acts as a filter and a feedback mechanism to identify issues that employess consider important and relevant.
The Political Calculation blog has come up with an interesting tool which can help you decide if, and also how, you should join in the guilty pleasure that is office gossip at your company.