Someone who supports or participates in something only because it is popular or successful.

plural of bandwagoner

A large wagon used to carry a band of musicians in a parade. / (figuratively) A current movement that attracts wide support.

plural of bandwagon

(politics) The practice of joining the prevailing side.

The tendency to jump on the bandwagon, i.e. to join a craze or trend, sometimes for profit.

(idiomatic) To profit from a craze; to join a trend.

(logic) argumentum ad populum.

(sociology) the observation that people often do or believe what they think many other people do.

plural of bandwagon fallacy