The decoy effect is a cognitive bias that means people can be persuaded to change their preference between two choices when a third (decoy) option is introduced. The decoy has to be clearly inferior in all respects to one of the offers and inferior in some respects to the other option to make them look more attractive.
Below is an example of decoy offer from The Financial Times. Notice the “Print Trial” offer is priced the same as the “Print and Digital” package so there is no real benefit in the former plan. As all choices are relative, the “Print Trial” helps make the other two more plans appear more attractive and may well encourage more people to subscribe to the the “Premium Digital Trial” plan compared to if the “Print and Digital Trial” and “Premium Digital Trial” were the only two options available.
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