Fad
A fad or trend or craze is any form of collective behavior that develops within a culture or social group and which impulse is followed enthusiastically by a group of people for a finite period of time.
Similar to habits or customs but less durable, fads often result from an activity or behavior being perceived as emotionally popular or exciting within a peer group or being deemed "cool" as often promoted by social networks A fad is said to "catch on" when the number of people adopting it begins to increase to the point of being noteworthy. Fads often fade quickly when the perception of novelty is gone.