The Decoy Effect
Five products, shown twice. Once with two real options, once with a third option that nobody should pick. The decoy never wins. It just changes which of the other two does. WIZ measures how many times that quiet trick worked on you.
I will show you ten shopping choices. Five products, each shown twice — once with two options on the menu, once with three. The third option is always engineered so that nobody, in theory, should pick it.
A rational shopper ignores the bad option entirely. Their pick between the two real options stays the same whether or not the decoy is on the menu. Most humans flip. You will see how often you did at the end.
Originally documented in Huber, Payne & Puto (1982). Made famous by Dan Ariely's Economist subscription study, in which a decoy nobody chose tripled the share of buyers who picked the most expensive plan.