the decoy effect

The Decoy Effect is a cognitive bias in which consumers change their preference between options when presented with a third, less attractive choice. For example, if you are choosing between a small coffee for $2 and a large coffee for $4, adding a medium coffee for $3.50 makes the large coffee seem like a better deal. This "decoy" influences our decision-making by making one option appear more appealing in comparison. Marketers often use this tactic to steer consumers toward a particular product by strategically adding options that highlight the value of the desired choice.