The Psychology of Persuasion by Robert Cialdini in 238 Words

Reciprocity

We are more likely to be persuaded to do something when it involves repaying an obligation. Example of giving a mint to customers in a restaurant

Scarcity

Point out the benefits - tell them what's unique about what you are offering - show them what they stand to lose by not taking up the offer

Authority

Signal to others what makes you a credible, knowledgable authority before you attempt to influence them. Get someone to praise you. That someone can even be related to your business (e.g. receptionist who refers to your expertise) or likely to benefit from it.

Consistency

Once someone is persuaded to make small voluntary,active, public contributions towards something, it is easier to then get them to do something bigger towards that goal, which they do to be consistent with their own model of themselves.

Liking

We prefer to say yes to people who are similar to us, who pay us compliments, and who cooperate with us. Do these before negotiating or talking about business.

Consensus

We do what others do when we are told what they do.

Examples:

• 75% of our guests reuse their towels, please do so as well.
  
• 75% of our customers order again within a month. Please use this code when you reorder….