The Contrast Principle
Also called perceptual contrast, the contrast effect
How we judge something depends on what we experienced just before it.
The contrast principle describes a feature of human perception: when two things are presented one after the other, the difference between them looks larger than it is. Something seems more expensive after something cheap, and cheaper after something expensive. In Dr. Cialdini's work it is not one of the seven principles but an amplifier that makes each of them land harder.
Showing the premium option before the standard one, presenting a smaller request after a larger one, setting a proposal beside the cost of doing nothing.
Every comparison offered should be a real alternative. Showing a deliberately poor option only to flatter the one you want chosen misleads the person deciding.
Foot-in-the-Door Technique
Agreeing to a small request makes people more likely to agree to a larger, related one later.
Door-in-the-Face Technique
A large request that is refused, followed by a smaller one, makes the smaller one more likely to be accepted.
Low-Ball Technique
Once people commit to a decision, they tend to stick with it even after its cost rises.
Know the terms. Now measure your own influence.
The Influence Assessment shows which of the seven principles you already use well, and which one is costing you.