PR-GB.com summarizes “Influence: The Psychology Of Persuasion” by Robert Cialdini.
Robin McKay writes (excerpt):
People are more willing to comply with requests (for favors, services, information, concessions, etc.) from those who have provided such things first. This is the old ‘give and take’ scenario – if I do this for you, will you do something for me? . . .
People are more willing to be moved in a particular direction if they see it as consistent with an existing commitment. . . .
People are more willing to follow the directions or recommendations of a communicator to whom they attribute relevant authority or expertise. . . .
People are more willing to take a recommended action if they see evidence that many others, especially similar others, are taking it. . . .
. . . People find objects and opportunities more attractive to the degree that they are scarce, rare, or dwindling in availability. . . .
. . . People prefer to say yes to those they know, like and find attractive.