You can use these concepts for good or manipulate people. Don’t manipulate people.
Loss Aversion
People are afraid of losing. The pain that people feel because of a loss is about two times as strong as the feeling of joy
Ownership
Sometimes people need to feel ownership of the project. Once people have put work into something, or have had a chance to hold onto it (physically or metaphorically), they start to own it. People can take ownership of a project that they haven’t started yet, or for their part of the project for which they have been allowed to have ownership. The higher the sense of ownership, the more engaged people will be. It seems like an obvious statement, that is worth repeating–because it’s true.
Relativity
Sometimes it is hard for people to understand what value you are bringing to the table. What people need to know is how your product stacks up relative to other things that they value. Think about how much you pay to an employee for a month (assume about $3000.) Think about saving that failing project. It is probably about the same value. And because you can see the relative value, you know how much a project rescue should cost.
These ideas are taken from Dan Ariely and Jeff Kessler’s book Dollars and Sense.