bandwagon
n. US //ˈbændˌwæɡən// UK //bˈændwæɡən// band·wag·on
n. An idea or activity that becomes very popular, causing many other people to start doing it too. You often hear this in the phrase 'jump on the bandwagon'.
n. A popular idea, activity, or cause that attracts growing support, often from people joining only after its mass appeal or success is apparent.
Many companies are jumping on the environmental bandwagon.
After the technology proved successful, rival firms were quick to jump on the bandwagon with their own versions.
The historian noted that investing during a bubble is not savvy strategy but merely jumping on a bandwagon that is already dangerously overcrowded.
From band + wagon.