Cialdini teaches us that we are persuasive if we are consistent or perceived to be consistent. Our dislike for erratic behavior is ingrained, and when we make a deal we want it to last. If we are doing the persuading, we want to show ourselves as consistent and point out any inconsistencies on the part of the other party.
An example is when someone says, “We never questioned this bill for ten years, but your increase is inconsistent with the past. We want you to keep the increase to inflation.”
A solution to this personal tactic is to find exceptions to your reputation of prior dealings. Change in circumstance may necessitate inconsistency: “Our suppliers’ prices have gone up 100% in the last ten years and we have increased our efficiency as much as we can, so we must increase our prices to continue providing consistent service.”