Rumor or gossip; it sounds so negative. But when you refrase it to "rumor around the brand" or "word of mouth" it all of a sudden sounds much more like something you can use to spread a message.
People love to talk about things they think others don't know about. It can be about a person, but also about upcoming situations or changes.
There is even a Basic Law of Rumor:
R~I x A x 1/C
And this codes back to:
Rumor is a function of Importance x Ambiguity x 1/Critical Sense
And now in understandable English:
When there is an important subject in a situation where the audience doesn't have much clearity on the subject, and if the audience isn't very critical about the resources they use for the information on the subject, there is a very large chance rumor will spread.
Just think about it. You think a co-worker is pregnant (important subject), but she doesn't tell (no clearity) and you ask a co-worker if he thinks she is pregnant (not a very reliable source) and you believe him if he confirms, you have a big rumor on your hands your co-worker is pregnant. Now, that is a nasty rumor.
But if you have a business and you want to introduce a new product. You just let slip somewhere, there might be something happening soon. Somebody hears this, doesn't have much information to go along, but he or she does talk about it with a friend. Who talks about it with a friend. Who talks about it with a friend. You have a rumor happening. And free publicity for your product launch.
Storytelling with a different twist.