I believe that gossip springs from hope. Some hope what is mummered is true because it brings something good, while others hope that what is mummered is true because it brings some level of satisfaction (good or bad). And yet others repeat what they hear to garner reassurance. There are so many reasons for gossip and even more for why gossip will always have life.
As a marketer at a law firm I find gossip to be an incredibly reliable barometer for knowing how the firm is doing. I probably hear less than a fraction of what flys about on any day but what I do hear is so telling.
It could be a wave of "did you hear's" about people in the firm. This points at moral and esprit de corps. It could be a "did you hear what he/she/them are saying about...". This usually points at decisions that have been announced. If the gossip starts, "everyone has pretty much agreed", it points at a growing consensus (right or wrong) about things few people can control.
Each may reflect on how the firm is presenting itself (outside of my control), or feeling about the state of things. Each are important when reflecting on what messages I am creating and the reality of what the market might receive.
Now it's true that gossip is... well, gossip. But people do react to it and make choices based on what they hear. As a marketer and champion of the brand (OK, maybe not champion but true-believer to be sure) I want to know anytime the message of the firm might be breaking down, or no longer hold the truth of what we are projecting.
Some gossip is wonderfully silly... but some bleeds to the street. Keep your ears open and gossip can be a great aid in understanding how all of the pieces are fitting together.