Harley-Davidson is the prototypical cult brand professors refer to in business schools everywhere. That's because its one of the earlier companies to truly develop a 'lifestyle' brand.
Much of the credit for that goes to the "Harley Owners Group" grassroots initiative the brand fired up in the mid-1980s. Membership started with dealership promotions and spread by word-of-mouth. People had groups they could meet up with and develop bonds — all based around the Harley brand.
It became more than an echo chamber because these people would go out and recruit more Harley enthusiasts to join. Eventually, they created a movement.
Despite an initial lack of acceptance, within a few years H.O.G. chapters started appearing around the country. The spread of these groups was guerrilla marketing at its best; membership was generated primarily from inexpensive promotions at dealerships and word-of-mouth. H.O.G. groups gave enthusiasts a structured way to meet, swap stories, and schedule rides with other evangelists.