People comply more readily with those who are similar, familiar, or complimentary to them.
Cialdini's finding that Tupperware parties outperform retail because the seller is a friend. Similarity and compliments both work even when the recipient knows they are instrumental.
In practice
- A supplier's account manager who went to the same school as the buyer wins renewals that a cheaper competitor does not.
- A canvasser who mentions living on the same street gets a longer conversation than one who leads with policy.