Fred Wilson explains:
Earned media is media you don’t buy but earn the hard way. PR is an example of earned media. Word of mouth is another. Earned media has been around forever. But it has now gotten a lot easier, thanks to the Internet and social media, to earn media for your brand, product, or self.
Fred gives the example of a taco truck in LA that is using Twitter to inform customers where the truck will be located to dish out its Korean barbecue tacos. Nearly 14,000 people follow the truck’s Twitter updates and many are willing to wait more than an hour for the upscale urban street food. KogiBBQ maintains buzz at almost no cost and creates an engaged community around its product.
This could be dublicated with most businesses. Its simple but its not easy. It takes creativity, dilligence to keep posting when nothing has happened after the first week and a product that is worth spreading.