Have you ever heard the saying " If your friends jumped off a cliff would you?" This mindset is called the bandwagon effect. If the majority of people are doing it then it must be right.
Examples of the bandwagon effect:
Planking according to Wikipedia Planking (or the Lying Down Game) is an activity consisting of lying face down, sometimes in an unusual or incongruous location. The palms of the hands are typically touching the sides of the body and the toes are typically touching the ground. Some players compete to find the most unusual and original location in which to play. The term planking refers to mimicking a wooden plank. Planking can include lying flat on a flat surface, or holding the body flat while it is supported in only some regions, with other parts of the body suspended. Many participants in planking have photographed the activity in unusual locations and have shared such pictures through social media.
Example of the bandwagon effect in sports:
According to Wikipedia a recent example in the United States is the Golden State Warriors, who rose to prominence by winning the 2015 NBA Finals, followed by a record-breaking 73-9 record the following year. The bandwagon effect can be seen in the statistics of the sales of point guard Stephen Curry's jersey. Curry merchandise sales in the first two weeks of the 2015–2016 season were 453% higher than in the first two weeks of the 2014–2015 season, including a 581% increase in sales of his jersey; his merchandise was a top-seller in 38 of the 50 U.S. states, and the Warriors' merchandise became the best-selling of any NBA team.