If people commit, to an idea or goal, they are more likely to honor that commitment, even if it no longer makes sense to. This is why marketers make you close popups by saying “I’ll sign up later”. Or in the image to the right, “No thanks, I prefer not making money” (not many people want to commit themselves to saying they prefer not making money!) Another example is American children being made to repeat the Pledge of Allegiance each morning. Use this to your advantage by posting on Facebook about your next resolution, like to exercise 5 times a week (or learn 1 new concept a week...).

People will do things that they see other people are doing. This is why in advertisements, certain social networks show you who of your friends like a page, or are going to an event. For example, in one experiment, one or more paid actors would look up into the sky; bystanders would then copy them, and look up to find out what was so interesting. At one point this experiment aborted, as so many people were looking up that they stopped traffic. See also the terrifying Asch conformity experiments.

People will tend to obey authority figures, even if they are asked to perform objectionable acts. Cialdini cites the Milgram experiments (asking people to deliver lethal electric shocks) and the many atrocities committed by soldiers “just following orders”. References in writing to people often include their titles and affiliation, so we’re more likely believe what they say.

People are easily persuaded by other people that they like (Cialdini calls this liking, but it is basically just the affect heuristic talked about previously). People were more likely to buy Tupperware if they liked the person selling it to them. Physically attractive people are more persuasive, being seen as more as kind or intelligent (called the halo effect). People are more likely to be persuaded by you if they like you. So be nice in arguments (and in life, it’s short)!

Perceived scarcity of a product makes consumers want it more. For example, saying offers are available for a "limited time only" encourages sales. To use scarcity to your advantage, run a promotion for your product that is limited by a time, or the number available.