What would be an example of contagious expansion diffusion?

Contagious expansion diffusion refers to the spread of a phenomenon, such as an idea or behavior, through direct contact with those who are already partaking in it, resulting in a ripple effect. This concept is exemplified by producing a viral online challenge that many join simultaneously.

In this scenario, the online challenge spreads quickly from person to person as individuals participate and share it with their networks, leading to widespread engagement. The nature of the challenge allows it to gain traction organically, driven by social connections and the rapid communication inherent in online platforms. This mechanism captures the essence of contagious expansion diffusion, where the spread is immediate and often unplanned, rather than reliant on structured methods or centralized dissemination.

In contrast, the other options involve different forms of diffusion. Creating a new product in a central city and selling it nationwide represents hierarchical diffusion, where an innovation spreads from a place of authority or popularity to others. Establishing a popular restaurant that expands into franchises signifies stimulus diffusion, where a foundational idea (in this case, the restaurant's concept) spurs adaptations in different locations. Moving a business from one downtown area to another does not reflect diffusion at all, as it is more about relocation than the spread of a cultural phenomenon or idea.