Once you do something good for people, they will feel indebted to you. Give them something: either it is information, a positive piece of advice or a free sample. Important condition here is that you have to give something first. Once you do that, people will want to give you something in return.
The less there is of something, the more valuable it appears to be. The more a thing is rare and uncommon, the more it will be wanted by people. A great example of this principle could be the waiting lines for the latest iPhone.
People want to follow others who look like they know what they are doing. They respect them, look up to them and even try to act like them. Giving the appearance of authority and credibility will increase the chances that people will comply with your requests.
People often seek consistency. They want to be loyal to their attitudes, values and beliefs and to be seen by other as consistent human beings. People also strive for consistency in their commitments. They are more likely to do something after they agreed to it. Ask your coworker to publicly commit to doing something and you will see how the principle of consistency works!
People are more likely to act like people they know and like. There are certain factors that make this principle work. People favor those things that are physically attractive (e.g.well-designed website), similar to them or who give them compliments.
The principle of social proof says that when people are uncertain about their decisions, they mindlessly tend to look to those around them to guide their course of action. People are always curious and they want to know what everyone else is doing. Especially their peers.