The "bandwagon effect" refers to the psychological phenomenon where individuals adopt certain behaviors, follow trends, or purchase items primarily because others are doing so. This tendency often leads to a rapid increase in popularity for specific products, ideas, or movements, as people want to be part of the majority. In social contexts, the bandwagon effect can be seen in various areas, such as fashion, technology, and even political opinions. For example, when a new smartphone model, like the iPhone, gains popularity, many people may choose to buy it simply because others have, rather than based on its features or benefits.