As a teacher I understand the value of repeating an idea or concept that I want to impart to my students. The long-term goal in that repetition is that they will cement something in their minds that will serve them in their years ahead. The short-term goal, which they are far more attuned to, is that they will score well on a test.
Repetition is sometimes the key to their retention, short or long term.
Advertisers and politicians understand this concept and use it to the maximum effect to gain profit and garner votes.
Pound away at the message and don’t let up because people’s attention is easily distracted. Their memories are notoriously short, and their commitments are short-lived in the absence of constant prodding. We are thus inundated in every aspect, every facet, every spare moment of our lives with words and images repeated over and over again to compel our attention.