Priming is a way of implanting a suggestion in someone's brain in a way such that the person's mind will be primed in a particular direction.  As I recall in Blink (Gladwell), people were given some sort of task in which they were meant to reorder sentences with jumbled words.  When they completed that task, they were observed afterward, not realizing it was the observation after that mattered, not the jumbled word test.  The jumbled words included words that we associate with aging, words like "old" or "gray" or "slow."  The people's minds were primed subconsciously with these "old" ideas, and they were observed walking more slowly and more bent over after the priming.  Essentially, priming is a deliberate effort at activating one's mind and/or emotions to accomplish a particular state or action thereafter. It is a little frightening to realize how easy it is to prime people, for example, for political or commercial purposes.