Robert Cialdini - Harnessing The Science Of Persuasion.pdf
Summary of Cialdini's six persuasion principles: liking, reciprocity, social proof, consistency, authority, and scarcity
The gentle science of persuasion (PDF)
Article on Cialdini's research on the principles of influence and persuasion, specifically on consistency. When people make active, voluntary, and public commitments, they try to be consistent with that commitment. Try to get people to make small commitments first.